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GRADUAL REDUCTION 


MILLING. 

A TREATISE ON THE 





LOUIS H. GIBSON, 

AUTHOR OF “ROUGH NOTES.” 





MINNEAPOLIS, MINN.: 

C. M. PALMER, P U B LISHKR. 
1885. 







Copyright, 

1885, 

By LOUIS H. GIBSON. 


INTRODUCTION. 


Where the reader is familiar with the general purposes of the writer, 
it is much easier for him to understand the details of the work. This 
book is intended to be one which has distinctively to do with milling 
and milling methods, but not with milling machinery. It is constructed 
on the idea that a mill is intended to make money, and the methods here 
given have in mind the production of the largest quantity of dour out 
of a given quantity of wheat, and of a quality such as will give it a 
good standing in the market. In general terms this is the purpose of 
the book. 

As to the plan: There is first a little milling history, and then a little 
more which has to do with the development of milling methods. After 
this there a e a number of chapters given to the general consideration 
of milling operations, which is followed by “A Journey Through the 
Mill," which considers the principles of milling in a more detailed way 
than in the previous divisions. After the journey th.ough the mill, 
mills ( f various sizes are considered one at a time. The consider¬ 
ation of mills of specified capacity gives opportunity for exact state¬ 
ments, and as the mills are larger, it may be shown how the details are 
worked out more closely. It may be said, however, that the diagrams 
given for the smaller mills might well be used for larger ones where 
the necessities of the case do not demand a more elaborate arrange¬ 
ment. The seventy barrel mill might be arranged for one of two hun¬ 
dred and fifty barrels per day by an increase in the amount of reduction 
and separating machinery. On the other hand, a fifty barrel mill might 
be arranged from a hundred barrel diagram by making corresponding 
changes in the machinery. 

In future editions of this book the writer designs to make such 
changes and additions as will keep it abreast of the times. 

LOUIS H. GIBSON. 

Indianapolis, Ind., July 20, 1885. 






































I . 

, 














































INDEX. 


American and Hungarian Methods of 

Wheat Cleaning_ 150-151 

Arrangement for Dust Collectors_225 

Aspirators_303 

Aspirator for Reductions_ 72 

Aspirators, Product of_401-402 

Bolting-188, 

Bolting Devices, Arrangement of_ 127 

Bolting Machinery, Improvements in_ 34 

Bolting, The Preparation of Stock for-125-126 

Bolting of Break Stock_ 187 

Bran, Broad, Clean_ 84 

Bran Compressing Machine_83-88 

Bran Duster_270 

Bran, P'ine P'eed and Screenings_83-84 

Break, First_ 161 

Breaks for a 50-Bbl Mill_378 

Break Flour Cut-Off_ 189 

Break Flour, Bolting_343 

Break Flour Reels for 500-Bbl Mill_421 

Breaks, General Consideration of the 

Various-99-102 

Breaks, Number for a Gradual Reduction 

Mill_ 182 

Capacity of Graders_400 

Capacity of Mills, Its Increase_ 59 

Centrifugal Reel, The_ 35 

Centrifugal Reel, Its Relation to the 

Bolting System-119-120 

Centrifugal for Dust Middlings_343 

Centrifugal Reel for Break Flour_342 

Changes in Mills, Their Effect upon the 

Marketing of the Flour_ 153 

Characteristics of Stock to be Reduced-- 410 
Chemistry, Its Relation to the Market— 65 

Classification of Products_217 

Classification of Reductions and Separa¬ 
tions_274 

Cleaning Machinery-143, 375 

Clothing of Reels and Scalpers Which 

Follow Fifth Break of 500-Bbl Mill_421 

Clothing of Reels and Scalpers Which 

Follow Sixth Break of 500-Bbl Mill_421 

Cloth, Numbers of_ 124 

Cloth, Relation of Numbers to Size and 

Feeling of P'lour_ 125 

Clothing of Scalpers for 50-Bbl Mill_379-380 

Commercial Considerations in Mill-build¬ 
ing-283-284 

Cost of Operating a Mill_285 

Cost of Flour_285 

Combination Mills_42-44 

Cut-Off from Break Flour Reel_ 189 

Diagram, Description of_240 

Diagram for 100-Bbl Mill_233 

Diagram for 200-Bbl Mill_250-253 

Diagram, Purposes of_23S 

Diagram of Purification for a Large Mill- 240 
Differential Motion, Effect in Practice-108-109 
Differential Motion, Effect of Variation— 107 

Disc Machines--338 

Disc Mill, Development of the- 46 

Disintegrators- 102 

Dust Collectors_223-224 

Dust Collector, The Original Idea of-223 


Dust Collector, Classification of Stock 

from-225—226 

Dust Middlings_187-188 

Dust Middlings, First_426 

Dust Middlings, Second_322—323, 426 

Dust Middlings from Hard and Soft 

Wheat-188 

Dust Middlings from 70-Bbl Mill_344 

Dust Middlings from 100-Bbl Mill_318 

Dust Middlings from 50-Bbl Mill_426-427 

Dust Middlings, Reduction and Separa¬ 
tion of- 42 6 

Dust Middlings, Second_426 

Dust Room_224 

Dust, Separation of_153 

Dusting of Middlings_341, 407 

Evans’ Dress, Modifications of_410 

Father of High Milling, The_17-18 

Feed, A Too Light_;_204 

P'eed on a Mill, The Proper Place to De¬ 
termine the Amount_80-81 

Feed, The Proper Place to Stop Making-83-84 

P'eed, Weight of, No Guide to Yield_" 84 

Feeding of Soft Stock-259-260 


fth 


Break-178 

fth Break in 100-Bbl Mill_293-295 

fth Break, Corrugations for_179 

Break of 500-Bbl Mill_421 

fth Reduction Stock, Quality of_179 

fth Reduction Middlings_ 180 

■Barrel Mill_373 

ne Feed, Screenings and Bran_83-84 

rst American Purifier, The_21-22 

rst Break_161 

rst Break Flour Reel, Clothing of_166 

rst Break, Flour from_166 

rst Break Scalper, Clothing of_164-165 

rst Break Flour, Proportion of_167 

rst Break, 70-Bbl Mill_337 

rst Break, 500-Bbl Mill_395 

rst High Grinding in America, The_20-21 

rst Marketing of Patent P'lour_ 22 

rst Purifier_ 18 

rst Purifiers in America_ 21 

rst Reduction_287 

rst Reduction, Machinery of_163 

rst Roller Mills_ 24 

rst Roller Mill in America, The_ 24 

irst Use of Roller Mills_23-24 

P'lour and P'eed Limited by Machinery in 

Mill_88-89 

Flour and Wheat Chemically Consid¬ 
ered--59-62 

Flour, Cost of_285 

Flour, Cheap, That of the Future_ 56 

Flour Dealers the Best Judges_ 69 

Flour, Doughing of_70-71 

Flour, Effect of Wheat on the Uniform¬ 
ity of.-94-95 

P'lour from Dust Middlings_ 192 

Flour from a Milling Standpoint_66-67 

Flour from P'irst Break_166-167 

Flour from Red-Dog Reduction_426 

Flour from Second Reduction-168 

Flour, Grading of-278 


F 

F 

F 

F 

F 

F 

F 

F 

F 

F 

F 

F 

F 

F 

F 

F 

F 

F 

F 

F 

F 

F 

F 

F 

F 
















































































































12 


GRADUAL REDUCTION MILLING. 


Flour, Granular- 7 2 

Flour, How to Grade-.--74-75 

Flour, Its Uniformity Compared with Uni¬ 
formity in Baking- 5 I- 5 2 

Flour, Low Grade-73 - 74 

Flour, Patent-7 2 ~73 

Flour, Production of Cheap-48-49 

Flour Production, The Limit of- 78 

Flour, Proportion of, Break- 169 

Flour, Quality of-284 

p'lour Reel for 50-Bbl Mill---381 

Flour Separations, 500-Bbl Mill-398 

Flour, Sixth Break-185-186 

Flour, Sixth Reduction-298 

Flour, Strength and Color of-69-70 

P'lour, The Place to Stop Making- 75 

P'lour, Troubles in Its Baking—--- 51 


Flour, Uniformity As a Value-giving El¬ 


ement- 94 

P'our Middle Breaks, Product 0L-190, 290- 291 
P'our Middle Breaks of 100-Bbl Mill—290-291 

Fourth Break-177, 339 

Fourth Break, Corrugations for- 178 

Grader as Affecting the N umbers of Cloths 

on Purifiers, The_206 

Graders, Capacity of- 4 °° 

Grades of Flour- 142 

Grading of Flour_278 

Grading of Reduced Tailings Stock-407 

Grading of Tailings-265 

Grading of Wheat_ 15° 

Grading of Wheat on Account of Hard¬ 
ness or Softness_ 162 

Gradual Reduction and Purification of 

Middlings_240 

Gradual Reduction Developed by the Pu¬ 
rifier _27-29 

Gradual Reduction Middlings-233-236 

Gradual Reduction Milling, The Devel¬ 
opment of- 25 

Gradual Reduction Mill, Reduction Sur¬ 
faces for_1x6-117 

Gravity Separator, A-203 

High Milling, Origin of, iti America- 21 

History of Milling_17-24 

Horizontal Wheat Cleaning Machinery— 375 
Hundred Barrel Mill, Introduction tO-280-282 

Hundred Barrel Mill, Machinery for_289 

Hungarian and American Methods of 

Wheat Cleaning-150-151 

Hungarian Methods of Purification_208 

Introduction of Rolls_ 23 

Low Grade Flour_73-74 

Low Grade Flour, Reduction in Percent¬ 
age of-147-148 

Low Grade, Proper Reduction of- 77 

Low Grade Stock_268 

Low Grade Stock, Grading of_268 

Low Grade Stock, Centrifugal Reels for 

-269-270 

Low Grade Stock, Relation to the Yield_270 

Machinery for 100-Bbl Mill_289 

Machinery for Small Mills_42, 290 

Machinery of a 50-Bbl Mill_385 

Magnet, The Horse-shoe_ 156 

Marketing of the P'irst Patent Flour_ 22 

Mechanical and Commercial Considera¬ 
tions for Mill Building_283-284 

Middlings, Definition of_196 

Middlings, Development of_191 

Middlings, Dusting of_341 

Middlings, Fifth Reduction_180 

Middlings, Fineness with Reference to 

Purification- 198 

Middlings, P'orm of_215-216 

Middlings from Various Breaks_217 

Middlings from Various Kinds of Wheat- 217 

Middlings, Gradual Reduction of_ 

31-32, 233-236, 238-249 


Middlings Grader for 500-Bbl Mill-40° , 

Middlings, Large, Why Not Usually As¬ 
pirated- 375 

Middlings Making, P'irst Break as Pre¬ 
paratory to- — *65 

Middlings Making- 1&-21 

Middlings Making, Early-18-21 

Middlings Making in America- 20 

Middlings Purification as a Wheat Clean¬ 
ing Process- ■— - 196 

Middlings, Purification of, 50-Bbl Mill .382-385 
Middlings, Purification of, for 70-Bbl Mill 

_ 348-357 

Middlings Purification, Reduction for- 99 

Middlings Purifier as a Broken Wheat 

Cleaner, The--- 3 1 

Middlings, Reduction of----254-258 

Middlings, Reduction for 100-Bbl Mill-307 

Middlings, Reduction and Separations for 

100-Bbl Mill_---311-314 

Middlings, Reduction for 7C-Bbl Mill-355 

Middlings, Returning of-x,-218 

Middlings, Second- 3 01 

Middlings, Sizing of-198, 227, 240-249 

Middlings, The Grading of.-205 

Middlings, The Size of-201-202 

Middlings, The Purification of-195 

Middlings, Their Scalping Before Sepa¬ 
rating Flour-12S-129 

Middlings, Uniform Travel of- 21 

Middlings, Variation in Proportion Made 215 

Miller, The Primitive- 17 

Miller, The Best-^- 75 

Millers, Their Changing Places- 55 

Milling Capacity, Over-rated-48-49 

Milling, History of_17-24 

Milling Machinery, The Proportion of--78-79 

Milling Matters, Organization in-132-133 

Milling Operations, Lack of Unanimity in 134 

Milling Progress, Means of-131 

Milling System Which Makes Money,A-49-50 

Mills, Changes In_52-53 

Mills, Increase in Capacity of_ 59 

Mills, Investments in_47-48 

Mills, Large Number of P'irst Class De¬ 
sirable_ 131 

Mills, The Effect of Different Manage¬ 
ment of_ 55 

Mill, 70-Bbl_331 

Mill, 100-Bbl_ 279 

Mill, 200-Bbl_250 

Mill, 50-Bbl_ 369 

Mill, 500-Bbl_389 

Mills, Size of- 274 

Mill, The Proportioning of the Various 

Parts of a_ 115 

Mills, Their Capacity_ 59 

Millstone Dress, Controversy as to Ne¬ 
cessity for a_414 

Millstone Methods of Reduction in Hun¬ 
garian Mills- 254 

Millstone Reduction on Middlings, Qual¬ 
ities of-410 

Millstones, Judicious Use of--.-_410 

Millstones and Rolls Combined for Re¬ 
duction of Middlings_256-257 

New Process Milling, Development of_-25-26 

New Process Milling, Origin of_21-22 

Number of Grades of Middlings_206 

Offal_ 82 

Oliver Evans’ Idea of Millstone Reduction 410 

Oliver Evans on High Milling_ 19 

Oliver P'vans, Quotations from_414 

Operation of a Mill, Cost of_ 285 

Origin of New Process Milling in Ameri¬ 
ca-21-22 

Over-Grinding _ 114 

Parr, Ignaz, The P'ather of High Milling 17-1S 
Patent P'lour, First Marketing of_ 22 























































































































GRADUAL REDUCTION MILLING. 


*3 


Patent Flour_72-73 

Percentages and Yields Calculated To¬ 
gether- Q1—Q2 

Percentages, Calculation of._89-01 

Principles of Milling Methods, The_ 20 

Purification and Wheat Cleaning, Analo¬ 
gy Between- 374 

Purification Diagram for Large Mill_ 240 

Purification, Early Methods of_18-19 

Purification for 100-Bbl Mill_300-506 

Purification of Middlings in 50- Bbl Mill_382-385 
Purification for the Purpose of Further 

Reduction_31-32 

Purification, Hungarian Methods of_ 1 208 

Purification of Middlings, The Reason for 41 

Purification of Dust Middlings_^7 

Purification of Sized Middlings_229 

I urification of 1 ailings_249, 315—3x7 

Purification of Middlings in 70 Bbl Mill 248-257 
Purification of Fine and Coarse Middlings 407 
Purification Originally an Experiment in 

Handling Middlings_ 26 

Purification System for 200-Bbl Mill_250-253 

Purification System for 100-Bbl Mill_231 

Purification System of 300-Bbl Mill_401-406 

Purification the Central Idea of Milling., 26 

Purification, The Limit of_196 

Purification the Path of Progress_ 2S 

Purifiers, Arrangement of_219 

Purifier as a Revolutionizer of Millstone 

Reductions, The_27-28 

Purifier as a Revolutionizer of Separa-' 

tions, The_ 28 

Purifiers, Clothing of___^_242 

Purifier Develops Gradual Reduction, 

The-27-28 

Purifiers, Exact Working Capacity of 212-213 

Purifier for Dust Middlings_191 

Purifiers, The First in America_ 21 

Purifiers, The Different Kinds of._201-204 

Purifier, The First_ 18 

Purifiers, The Operation of_212 

Purifiers, The Principles Which Regulate 

the Working of-213-214 

Purifiers, Means of Regulating the Ca¬ 
pacity of-214-215 

Purpose of Milling History, The_ 17 

Quality of Flour_284 

Red-Dog-426 

Red-Dog from 100-Bbl Mill_ 34 

Red-Dog in 50-Bbl Mill_428 

Red-Dog, Reduction of, by Millstones_426 

Red-Dog, Second___426 

Red-Dog Stock, Grading of_426 

Red-Dog Stock, Origin of_426 

Red-Dog Stock_268-273 

Reductions and Separations of Middlings 

100-Bbl Mill_ 283, 307 

Reductions Better Understood than Sep¬ 
arations_ 136 

Reduction, First, Machinery of_168 

Reduction for the Purpose of Purification.31-32 

Reductions, Number of_274-275 

Reduction of Dust Middlings_320 

Reduction of Middlings in 500-Bbl Mill_419 

Reduction of Middlings in 500-Bbl Mill, 

Means for_410 

Reduction of Tailings in 70-Bbl Mill_261 

Reduction Machines, Relative Severityof 

Various_101 

Reductions, Their Relation to Separations 

-118-119 

Reductions, The Different Classes of- 98 

Reels, Action of Various Kinds of Stock 

in_121-122 

Reels, Clothing of_419 

Reels for Middlings, Clothing of.-255 

Reels for Separating Reduced Middlings 
--255-257 


Reels, Speed of._ I2 2 

Removal of Impurities_201 

Roller Machines, The First_ 23 

Roller Machinery, Development of._30-38 

Roller Machinery, Improvement in_ 37 

Roller Mills, First in America_ 24 

Roller Mills, First Use of_ 23 

Roller Mills, History of_-.23-24 

Rolling Screens for 70-Bbl Mill_ 434 

Rolling Screen, The_153-154 

Rolls and Millstones Combined for Re¬ 
ducing Middlings_256-257 

Rolls, Dress of Second Break_170-171 

Rolls, Kvi Is of Excessive Pressure of 

Smooth-109-m 

Rolls, Second, Break, Running of, With¬ 
out Change of Feed_173 

Rolls, Smooth-97, 106, 202, 259 

Rolls, Smooth, as Reduction Machines-107-108 

Rolls, Smooth, as Purifiers_106-107 

Rolls, Smooth, for One of the Last Breaks 183 
Rolls,Smooth,Setting to Produce Best Re¬ 
sult -109-110 

Rolls, Smooth, Stock Running Over the 

End of-262 

Rolls, Sizing_ 97 

Rolls, Speed of_261 

Rolls, Sizes Made by Different Manufac¬ 
turers -39-41 

Scalpers, Clothing for_ 103 

Scalpers, First Break_164 

Scalpers for Sixth Reduction_297 

Scalpers, Length of for Various Breaks.- 105 

Scalper, Third Break_ 177 

Scalper, Sixth Break_185 

Scalpers, Zinc for Clothing_ 168 

Scalping Arrangements, Value of Proper 

----129-130 

Scalping Cloth, the Proper Stock to Take 

Through-102 

Scalping Cloths, the Use of Tail_125 

Scalping for Second Reduction_170 

Scalping Middlings Before Separating 

Flour-128-129 

Scalping Numbers, Development of for 

Various Breaks_103 

Scalping Numbers, Relation of the Corru¬ 
gations to_103 

Scalping Reels for Reducing the Yield_272 

Scalping Reel for Fourth Break_ 178 

Scrapers for Smooth Rolls_263 

Scratch Rolls_112 

Screenings, Fine Feed, and Bran_83-84 

Secotid Break Rolls, Dress of_170-171 

Second Break, 70-Bbl Mill_339 

Second Middlings, Reduction of_419 

Second, Third and Fourth Breaks, 500-Bbl 

Mill- 397-398 

Second Reduction_ 168 

Separating Machinery, Its Development- 33 

Separation of Reduced Stock_419 

Separation of Stock-421 

Separations_227 

Separations, Classification of_276-277 

Separations and Reductions for 100-Bbl 

Mill_283 

Separations of Reduced Material_2o8-2ii, 256 

Seven Breaks-183 

Seventh Break, A-421 

Seventy Barrel Mill-321 

Seventy Barrel Mill Diagram-366 

Sharp Material, The Reduction of the 

Proportion of_125-126 

Sieve, An Over Supply of Stock on the-213-214 

Sieve Grader, A_205-206 

Sieve, The Proper Covering of the-212 

Sixth Break on 500-Bbl Mill-421 

Sixth Break, The-182-184 

Sixth Break Scalper- 185 























































































































*4 


GRADUAL REDUCTION Mil,LING. 


Sixth Break Flour, Bread from_185-186 

Sixth Reduction, Separation of Stock 

from-298 

Sixth Reduction Flour-298 

Sixth Reduction, 100-Bbl Mill-296-297 

Size of Mills_274 

Sized Middlings, Purification of_229 

Sizing, Method of_228-229 

Sizing of Middlings—198, 227, 240-249, 404-407 

Sizing of Tailings-407 

Sizing Rolls____—97, 245 

Sizing Rolls in 100-Bbl Mill_304 

Small Mills, Consolidation a Necessity— 45 

Small Mills, Finer Corrugations on-104 

Small Mills, Machinery for-42, 290 

Smooth Rolls-106, 202 

Smooth Rolls as Reduction Machines-107-108 

Smooth Rolls as Purifiers-106-107, 198-199 

Smooth Rolls, Evils of Excessive Press¬ 
ure on_109-ui 

Smooth Rolls for One of the Last Breaks. 183 
Smooth Rolls, Limit of Reduction Power 

of_ 11, 362 

Smooth Roll Reductions- 97 

Smooth Rolls, Scrapers for-263 

Smooth Rolls, Setting to Produce Best 

Result_109-110 

Smooth Rolls, Stock Running Over the 

End of-262 

Smooth Rolls, The Early_ 37 - 3 $ 

Smooth Rolls, Their Practical Operation 259 

Smutter, The-,\_156-157 

Soft Stock, Feeding of-259-260 

Speed of Rolls_261 

Stock, Its Proper Condition to Bolt_128 

Tailings-264-267 

Tailings, Aspirating of_265-266 

Tailings, Coarse___407 

Tailings, Development into Purified Mid¬ 
dlings, Flour and Rough Tailings_410 

Tailings, Fine-407 

Tailings for 500-Bbl Mill_407 

Tailings, Purification-249 

Tailings, Rough-407, 426 

Tailings, Rough, Composition of_407 


Tailings, Rough, Purification, Reduction 

and Separation of._: 426 

Tailings, 70-Bbl Mill_358 

'failings, in 100-Bbl Mill_315-317 

Tailings in 500-Bbl Mill_427-42S 

Tension Springs for Smooth Rolls_ 261 

Third Break, The_ 175 

Third Break, Corrugations for_ 170 

Third and Fourth Breaks, 70-Bbl Mill— . 339 

Third Break Scalper, The_ 177 

Uniform Low Grades Not Possible When 

High Grades are Uniform_ 79 

Uniform Travel of Middlings_221 

Weigh Hopper, The_ 155 

Wheat and Flour Chemically Considered 59-62 

Wheat, Hard and Soft_ 286 

Wheat, The Cleaning of._141, 151, 374-376 

Wheat Cleaning as a Purifying Process_31 

Wheat Cleaning for 70-Bbl Mill_233 

Wheat Cleaning for 50-Bbl Mill_271 

Wheat Cleaning of 500-Bbl Mill_39 I- 394 

Wheat Cleaning, Influence of Yields-374 

Wheat Cleaning Machinery_15S-159 

Wheat Cleaningof the Spring and Winter 

Wheat Section_376 

Wheat, Grading of_150, 162 

Wheat Heaters- _ _ -..96-97, 395 

Wheat Milling, The Purposes of_ 28 

Wheat Mixing_ 162 

Wheat Purification, The Purpose of. Pre¬ 
vious to Reduction_ 141 

Wheat, Reduction of Hard and Soft_95-96 

Wheat, The Size of_ 95 

Winter Wheat Millers and New Process-22-23 
Yields and Percentages Calculated To¬ 
gether -91-92 

Yields, Buhr and Roller Compared_86-87 

Yields, Comparison Under Old and New 

Systems_ 89 

Yields from Cleaned Wheat_:_ r 88 

Yield Reduced by Scalping Reels_272 

Yield, Reduction of, by Gradual Cleaning 

Machinery_147-149 

Yields, The Relation of, to the Quality of 
the Flour_ 77 










































































THE HISTORY AM) DEVELOPMENT 


Gradual Reduction Milling. 

















CHAPTER I. 


the PURPOSE OF MILLING HISTORY-THE FATHER OF HIGH MILLING—THE 

FIRST PURIFIER—EARLY MIDDLINGS MAKING IN FOREIGN COUNTRIES— 
MIDDLINGS MAKING IN AMERICA—THE FIRST HIGH GRINDING IN AMERICA 

-THE FIRST AMERICAN PURIFIER-THE MARKETING OF THE FIRST 

PATENT FLOUR-WINTER WHEAT MILLERS AND NEW PROCESS-THE IN¬ 
TRODUCTION OF ROLLS IN FOREIGN COUNTRIES-THE FIRST ROLLER 

MACHINES-THE FIRST PORCELAIN ROLLS—THE DEVELOPMENT OF 

GRADUAL REDUCTION MILLING—THE FIRST ROLLER MILL IN AMERICA. 

In a work of this kind, which has only to do with the milling of the 
present time, it is hardly necessary to consider the past, except in 
so far as it has to do with the development of recent methods. His¬ 
tory, for its own sake, will not be considered. The history of milling, 
to him who cared to write it, would be the history of the reduction and 
purification of cereals for bread making purposes. The history of 
purification in general, without special reference to middlings, would be 
the complete history of milling. The primitive savage who, in ham¬ 
mering out his grain on a rock, stopped to pick out a bug or a stick, 
expressed his idea of purification, and, for the time being, was satisfied 
with it; but as he looked around, he advanced, he discriminated more 
closely as to what he should eat or wear; he took out more of the im¬ 
purities from his flour; wore better clothes, and has been doing the same 
thing ever since. His first efforts expressed the germ idea of milling; 
that is, purification. 

As this work has to do with middlings milling, as now understood, it 
may be well to give the history of its development, beginning with the 
time when the value of middlings, as a milling product, was first recog¬ 
nized. 

Ignaz Parr is spoken of as the father of high milling. He was born 
July 22nd, j 776, in Tattendorf, Lower Austria, and died Sept. 6th, 1842, 
in Lichtenworth, Austria. Parr made the experiment of re-grinding 
the separated grits, and made a Hour which he called “Extract Flour;” 
and such was the demand for this flour that he could not supply it. He 
( 2 ) 


i8 


GRADUAL REDUCTION MILLING. 

* 


purified the grits by hand sifting. After various experiments, he con¬ 
structed, with the aid of a cabinet maker by the name of Winter, the 
first purifier. Fig i is a cut of Parr’s machine. A is the hopper from 
which the broken grains fall into the purifier; O is an opening through 
which a current of air is drawn in upon the falling middlings. The 
heaviest fall through the division B\ the 
next heavier fall at C. What falls through 
B encounters a current of air from O, 
which carries the lighter to C, and the still 
lighter is carried over to D. Thus the 
currents separate the middlings into three , 
grades. 

Down to the beginning of this century, 
the construction of flouring mills was ex¬ 
tremely simple. There was a single pair 
of millstones and a single bolt of which 
the motive power might be wind, water, 
horses or cattle. Everything else must be accomplished by manual 
labor; and instead of elevators and conveyors there were shovels, bar¬ 
rels and tubs. In the early part of this century the first decided im¬ 
provement resulted in the process of high milling which had its origin in 
the neighborhood of Vienna. This is shown from the fact that in 1807 
a product was sold in Austria and Germany under the name of Wiencr- 
gries ('Vienna middlings), which shows clearly that high grinding was in 
practice. In those days high grinding was very simple. The millstone 
broke the wheat, the meal passing into a bolting box, which was a box 
with a screen under it, at the end of which stood a man with a riddle 
to separate the bran from the middlings, which was brought against it. 
Another man then took the separations of the middlings in hand. He 
stationed himself between two doors or open windows where there was 
a draft of air to which he exposed the middlings while shaking on a sieve. 
To a certain extent the bran was blown away and the middlings were 
afterward ground by themselves and the bolting done on another cloth. 

Another method was as follows: The coarser particles were separated 
by agitating tubs or boxes having sieves across the bottom, the sieves 
being commonly made with hair. The bran worked to the surface be¬ 
cause of its lightness and was, from time to time, separated by means 
ol a little shovel, leaving the middlings at the bottom. 





















GRADUAL REDUCTION MILLING. 


l 9 


The development of high milling in Budapest was brought about in 
a peculiar way. The mills of that section were run by current wheels, 
that is, the water wheels stood out in the current and in that way trans¬ 
mitted the power to the mills. It so happened at one time that they 
had extremely low water, so low indeed, that the mills could not be 
operated in the usual way. The wheat could not be reduced at a single 
reduction, and, as an expedient, the experiment of reducing the wheat 
gradually by the millstones was undertaken. 'To the surprise of all 
who tried it, the flour was of most excellent quality, so good indeed as 
to lead to other experiments which developed high milling. 

Previous to the introduction of the purifier in this country, the in¬ 
genuity and skill of the miller was devoted largely to the end of reduc¬ 
ing his wheat without the production of middlings. Everything that 
was done for the buhrs, their speed, their dress and their general handling 
had this one object in view. Middlings were regarded as a product 
which was unavoidable in the later years of the old process of milling; 
and, as such, there were efforts made to derive something more than 
feed from this material. For many years previous to the introduction 
of the purifier, middlings were regarded as a material from which flour 
of an indifferent character might be made. 

Oliver Evans expresses himself on this point in the last edition of 
1836, as follows: “ Although we may grind the grain in the best manner 
we possibly can so as to make any reasonable dispatch, there yet will 
appear in the bolting a species of coarse meal, called middlings and 
stuff, a quality between superfine and shorts, which will contain a por¬ 
tion of the best part of the grain, but in this state they will make very 
coarse bread, and consequently will command but a low price. For this 
reason it is always profitable to the miller to grind and bolt them over 
again, and to make them into superfine flour and fine middlings. Mid¬ 
dlings are generally hoisted by tubs and laid in a convenient place on 
the floor in the mill loft near the hopper boy until there is a large quan¬ 
tity gathered. When the first good opportunity offers, it is bolted over, 
in order to take out all that is fine enough to pass through the superfine 
cloth.” Thus we see that they were dusted. ‘ k The middlings will pass 
through the middlings cloth, and will then be round and lively and in a 
state for grinding, being freed from the fine part that would have pre¬ 
vented it from feeding freely. The small specks of bran that were be¬ 
fore mixed with it being lighter than the rich round part, will not pass 


20 


GRADUAL REDUCTION MILLING. 


through the middlings cloth, but \vi,l pass on to the stuff cloth. The 
middlings will by this means be richer than before, and when made fine 
may be mixed with the ground meal and bolted into superfine flour.” 
Here we see that the middlings were purified on the reel, and were after¬ 
ward ground and bolted into what was then called superfine flour. It 
will also be noticed that they did not wish to make middlings, but as, in 
spite of all efforts to the contrary, they would make a small quantity, 
the next thing to do was to make the best of it. 

A translation of a description of the mills of St. JVlaur, in the neighbor¬ 
hood of Paris, made in 1859, speaks of “the part next to the husk, that 
is to say, the hardest part and the most refractory to the millstones, but 
at the same time the richest in nitrogen and the most sensitive to the 
action of the leaven. It is scarcely a hundred years since this precious 
article of food has been in use. Previous to that time was it not only not 
sought after, but it was spurned with scorn under the contemptuous name 
of ‘ Champagne’ flour. A royal ordinance in 1658, under the severest 
penalties, prohibited its use for human food and consigned it to the cat¬ 
tle.” We notice again that they speak of the part which is refractory to 
the millstones. They would reduce it if they could. 

During the later years of milling by the old process, it was not an 
uncommon thing to take that portion of the middlings which had passed 
through a No. 6 or 7 cloth and re-grind them on a buhr by themselves. 
This produced a grade of flour which stood between the first flour 
and the low grade. Its value was so much below the regular wheat 
flour, however, that no effort was made to increase its quantity. The 
earlier efforts at purification in this country were by blowing a blast 
into the reels in various ways. This was tne foundation idea of the 
old Cochrane patent, which was granted to Coggswell & McKiernan, 
June 12th, i860. 

The first account that we have of absolute high grinding was at North- 
field, Minn., in 1866. A farmer asked that some of his wheat be ground 
in that way, and without particular regard to the yield, the flour was 
produced, which, when examined by the miller, proved to be of most 
excellent equality. The owners of this mill became convinced that high 
grinding was the coming system, and they set to work to devise means 
of saving the large middlings and perfecting the system. Many differ¬ 
ent ways were tried with more or less success, but yet their experiments 
were not satisfactory. One method tried was to blow a blast of air 




GRADUAL REDUCTION MILLING. 


2 I 

through a falling stream of middlings, but the middlings were not sized 
and this was abandoned as impracticable. Then the middlings were run 
into an eight-sided reel, and a blast of air blown through it. This plan 
was the most successful attempted. Another experiment was to run 
the middlings into a pile and let the impurities come on top. Flour was 
made from middlings in this mill and kept in stock as its best Hour. 

In 1868, Nicholas and E. N. La Croix, at Faribault. Minn., were 
operating a machine which was described as a box with a sieve on top of 
it and a blast of air under the sieve. This is the earliest account that 
we have of the use of a sieve and air current for the purification of 
middlings in this country. It is evident, however, that the idea of this 
machine was developed from those of French design and construction. 

In February, 1870, E. N. LaCroix described to Mr. Geo. H. Chris¬ 
tian, manager of the Washburn mill of Minneapolis, a machine for clean¬ 
ing middlings which he had seen operating in France, and solicited an 
order from him to build such a machine, and he accepted La Croix’s 
proposition to build it on trial. However, this machine was not ready 
for use until some time in 1871, after which time it was run regularly 
for several weeks. The success of this machine was sufficient to indi¬ 
cate its great value. 

Mr. Christian ordered another machine, the mechanical details of 
which were somewhat different, though the underlying principles were 
the same. 

As this purifier was subsequently the cause of one the most bitter and 
stubbornly contested battles of the whole purifier war, a description 
of its principal features will be of interest. The frame was about six 
feet in length, nearly the same in width, and was enclosed in the manner 
usually followed in building such machinery. There were two sieves, 
placed side by side, driven from the same shaft, and separated from each 
other by a partition which divided the air chamber above the sieves 
longitudinally into two compartments, and extended from the top cov¬ 
ering of the frame down to and below the level of the sieve fiames. 
r pfig]-g was an exhaust fan on top of the machine, and each of the an 
spaces above the sieve communicated with it through separate openings 
fitted with valves, so that the force of the air current through the cloth 
o either sieve could be varied at will. The usual provision tor the 
admission of air below the sieves was made. At the head ot the ma¬ 
chine, some distance above the sieves and arranged transversely to them, 


22 


GRADUAL REDUCTION MILLING. 


was placed a grading reel clothed at the head with finer silk than the tail, 
having its conveyors and spouts so constructed as to deliver the material 
coming through the fine silk to one sieve of the purifier, while that com¬ 
ing through the coarser cloth was fed to the other. The purified mid¬ 
dlings from these machines were ground on stone, the meal was bolted in 
separate reels provided for the purpose and the flour mixed with the 
first flour, producing a grade the demand for which was ten times greater 
than could be supplied, and which sold for fifty cents per barrel more 
than the best price obtained for the product of the mill before the im¬ 
provements were made. 

The history of the marketing of the first product of patent Hour is 
pertinent in this connection. As commonly understood it is as follows: 

Near the close of 1871, Mr. Archibald secured a La C r oix purifier, 
and, taking it into the attic of his mill at Dundas, began to experiment. 
After much labor and continual trouble, 100 barrels of middlings care¬ 
fully prepared and cleaned were finally accumulated and reduced to 
flour. A sample was sent by express to Plummer & Co., of New York, 
who had been handling the firm’s flour, with the request that it be put in 
the hands of a good baker, and the flour and bread from it exhibited at 
the corn exchange. When the flour was shown there those who saw it 
could hardly be made to believe that it had been made from spring 
wheat. The hundred barrels were divided and sent to New York and 
Boston. The success of the experiment in marketing this flour justified 
its manufacture as a regular grade. In a few months the spring wheat 
patents had advanced three dollars a barrel over and above the price of 
their former regular grades. 

Before the close of the year 1872, patent flour was selling for $14 in 
New York, and for several years the price varied but slightly. For two 
or three years the price of wheat fluctuated between sixty cents and a 
dollar and twenty-five cents a bushel, but the price of flour never 
changed, $10 at the mill being the fixed figure. It may readily be seen 
that these were the palmy days of milling, and that the foundations for 
the great milling fortunes of the Northwest were laid. 

The winter wheat millers gradually took up with the purifier idea. In 
the meeting of the Millers’ National Association at Toledo in July, 1873^ 
we find that many millers of that section were engaged in discussing 
these machines. In February, 1874, at the meeting of the National 
Association at Chicago, this matter came up for discussion in a regular 


GRADUAL REDUCTION MILLING. 


2 3 


way. JVIr. Kern, of Milwaukee, who can hardly be spoken of as a win¬ 
ter wheat miller, however, mentioned the fact of his having a purifier in 
operation in his mill, and that he had just purchased eight others. Sev¬ 
eral of the winter wheat millers spoke during this discussion favoring the 
system of the purification of middlings, though it was evident that the 
adoption of middlings purifiers was by no means general at this time. 
1 hey were still regarded as being in the experimental stage by many 
millers. It is not clear to whom, among the winter wheat millers, belongs 
the honor of having first introduced the purifier. It is a matter which 
is still under discussion. 

The use of rollers in doing the work of millstones and in displacing 
them, dates back to the year 1820, when Collier of Paris, JBolinger at 
Venice, and Ilelfenberger in Switzerland, erected Hour mills fitted with 
rolls instead of stones. These mills, however, did not succeed, though 
it is alleged that the fault had to do with the machines rather than the 
system of reduction by rolls. In 1830 Mr. Sulzberger, of Frauenfeld, 
Switzerland, succeeded in constructing a roller machine on a more im¬ 
proved system than the others. He established a company to introduce 
them throughout the continent of Europe, and many mills were actually 
built in Milan, Venice, Mayence, Stettin, Leipsic, Mannheim and Pesth; 
and for a time it appeared with great success, yet the fact is, that nearly 
all of these mills failed or adopted the old system of grinding. The 
cause of this failure was ascribed to the fact that it was impossible to 
find a sufficient number of skillful and intelligent workmen to operate 
the mills. A proof of this is found in the fact that one of the earlier 
mills which was built in Pesth, the Pesther Cylinder Mill, succeeded and 
continued to work this system with great profit. The Sulzberger ma¬ 
chine consisted of three pairs of rolls arranged one pair above the other. 
Each roll was six inches in diameter and cpatained two hundred grooves 
in its circumference. The motion was differential, the usual speed for 
the slow roll being two hundred and sixteen, and the fast roll two hun¬ 
dred and twenty-nine. Rolls were used to break the wheat and the 
middlings, before they were used to reduce the middlings into flour. 

It would appear that the first complete roller mill was the reconstructed 
Pesth Cylinder Mill, which was working in 1867. This mill had two hun¬ 
dred and ten pairs of rolls arranged in five sections. Two of these sec¬ 
tions were arranged for the production of middlings and the other three 
for reducing the middlings into flour. As a mill which used rolls to re- 


24 


GRADUAL REDUCTION MILLING. 


duce wheat and to grind middlings as well, this mill long had the 
monopoly. Until 1864 only one mill in Venice, one in Switzerland 
and another in Germany had adopted this system on a smaller scale. 
However, the Pesth mill seems to have been the first prominent success 
in this way. 

| It would appear that a mill designed by Naetf, of Pesth, was the next 
successful roller machine which came prominently into use after the 
Sulzberger. It was manufactured by Escher, Wyss & Co., of Lees- 
dorf, near Vienna. This was in 1864. It was a four high mill, single 
rolls being placed one above the other. 

Early in 1874, Mr. Wegmann, of Naples, brought out his porcelain 
roll and introduced it in various stone mills of Pesth. It was origin¬ 
ally used for sizing middlings rather than reducing them to Hour. Pre¬ 
vious to 1874, rollers for the reduction of wheat and middlings were not 
generally used even in Austria and Hungary, the cost of a complete set 
being from a thousand to twelve hundred dollars. In 1875 rollers be¬ 
gan to be used extensively in German mills, and at an exhibition of 
milling machinery in 1875, * n Vienna, ten firms were represented, and at 
another exhibition at Nuremberg in 18 76,fifteen roller mills were exhibited. 

Now, while it would appear that the system of roller milling was gen¬ 
erally understood for many years previous to its general successful in¬ 
troduction, however it was only during 1875 that the roller flour of Pesth 
began to achieve a world-wide reputation, or in fact was generally appre¬ 
ciated outside of that country. 

The first roller mill in this country was the hundred-barrel experi¬ 
mental mill built in one end of the Washburn“ C ” mill in the winter of 
1878-9. It contained sharp corrugated rolls, smooth iron rolls and 
porcelain rolls, and made three regular grades of flour at five reductions. 
The success of this mill led to the general introduction of rolls into this 
country. This mill is generally spoken of as the experimental mill, and 
we of this country are disposed to take a great deal of credit to our¬ 
selves in the matter of roller and gradual reduction mills. From the 
history given above it must appear that we are wrong in all this, and 
that we are justified in claims of invention only in so far as applied to 
the adaptation of this system to the automatic mechanical arrangements 
of American mills. It would appear from the present practice in Ameri¬ 
can mills that the nearer we approach Hungarian methods as a system, 
the more successful and profitable is our milling. 


CHAPTER II. 


DEVELOPMENT OF NEW PROCESS AND GRADUAL REDUCTION METHODS- 

PURIFICATION THE CENTRAL IDEA OF MILLING—PURIFICATION ORIGIN¬ 
ALLY AN EXPEDIENT IN HANDLING MIDDLINGS-THE PURIFIER AS THE 

REVOLUTION IZER OF MILLSTONE REDUCTIONS-THE PURIFIER AS A 

REVOLUTIONIZER OF SEPARATIONS-THE PURIFIER DEVELOPS GRADUAL 

REDUCTION-PURIFICATION THE PATH OF PROGRESS IN MILLING AF¬ 

FAIRS. 

In the previous chapter we have a few facts in regard to the develop 
ment of new process and gradual reduction milling. It has to do with 
facts independent of the reasons which led to the development of those 
facts. We read that the middlings purifier came into use at a certain 
time and that certain roller mills were in successful operation at certain 
other times. There was a reason for the introduction of the purifier, 
and for the development of gradual reduction methods. There is a dis¬ 
tinct relation existing between the purifier and the latter methods of 
reduction. 

In order that this may be made clear it may be well to consider, in 
short form, the reason for middlings milling—the reason why it is prefer¬ 
able to reduce wheat to middlings rather than directly to Hour. It has 
already been said that the central idea of milling is purification. Mid¬ 
dlings, as we have seen, were originally a troublesome material to the 
miller. His endeavors were in the direction of reducing the proportion 
of such stock. Having reached the limit of possibilities, and a consid¬ 
erable portion of middlings still remaining, there was a lurking thought 
in his mind which afterward took form in the purification of these mid¬ 
dlings. As the miller of the earlier days saw this stock, examined it, 
tasted it and knew its richness, he could not but think, if he thought 
anything about it, that here was a material which should be utilized in a 
more profitable way than that of selling for mill-feed. It was not at all 
uncommon to see millers running this stock over a No. 6 or 7 cloth and 
then re-grinding its products. This was one of the earlier practical 
forms of middlings purification in this country. 


26 


GRADUAL REDUCTION MILLING. 


While the process of purification which developed as an expedient for 
the taking care of a material which the miller could not but produce, 
however close he might grind with his millstones, the handling of this 
material developed an entirely new principle in milling. The purifier 
not only took this material and rendered it more valuable than feed, but 
more valuable than the highest grade of tlour formerly made. This be¬ 
ing so, an increase in the production of middlings was the next work ot 
the miller. Why and how could the purifier do this? 

The process of purification commences with the wheat, and the purity 
of the tlour is largely influenced thereby. If it were possible to entirely 
remove all of the impurities of the wheat berry previous to its re¬ 
duction, the purifier never would have been used; it would not have 
been necessary. 

As purification could not be complete as a wheat cleaning operation, 
as the impurities were something more than foreign substances—some¬ 
thing more than external attachments or coatings—it was necessary that 
the wheat be broken and that these external and internal impurities 
which were a part of the wheat berry be removed. The reduction ma¬ 
chinery having partially detached such impurities, it remained for a 
machine to be devised which would separate such stock from the reduced 
material. Such a machine was realized in the middlings purifier. While 
the wheat cleaning apparatus removes the foreign impurities, and those 
which are readily detachable from the berry itself, the middlings purifier 
is the wheat cleaning apparatus which removes the impurities which are 
not foreign to the wheat, which are not detachable from the grain itself 
excepting subsequent to its reduction. The introduction of the purifier 
revealed a new principle. It more than accomplished its original pur¬ 
pose. While the original aim was that it should act as an auxiliary—a 
helper to the old process—it became the father of an entirely new idea 
and new principle in milling. 

The natural thing to do, after first witnessing their work, was to raise 
the millstones, to grind higher, which was done. Next the miller ob¬ 
served that by taking off feed he could make more middlings. Then 
he reduced the proportion of land on his buhrs, and finally he reduced 
their speed. While previous to the development of the purifier the 
millstones were grinding from eighteen to twenty-five bushels an hour, 
their speed was reduced to one hundred and twenty and thirty and their 


GRADUAL REDUCTION MILLING. 


27 


feed trom the above to six, seven and eight bushels an hour, and all 
with the view of making more middlings. 

It would be difficult to say when the first pair of smooth rolls was 
used in this country, or for what purpose. Among the first uses to which 
smooth rolls were put was the breaking of the wheat previous to its 
reduction by millstones. Yet it could hardly be called a breaking, as 
its tendency was to a slight crushing, and it required an examination to 
assure one that it had been operated on at all. 

After these changes there was a rest for a time; at least there were 
no signs of the activity of inventive minds. Mills were built embody¬ 
ing these principles and details, and, as the grinding was heavier, at the 
first reduction, the bran products were necessarily heavier. This sug¬ 
gested an additional reduction, and as the middlings remained unreduced 
after purification, additional reductions had to be supplied here. Thus 
the purifier added the bran cleaning reductions and the following reels, 
and one, two or more reductions for the middlings and the reels which 
separated this stock. Thus, even at this time, we had a species of 
gradual reduction. A year or two before the introduction of rolls an¬ 
other great change was made in the millstone dress. The eye of 
the buhr, as a portion of its grinding surface, was entirely removed. 
Most mills with four foot buhrs reduced the surface to nine inches of 
skirt with the usual slant toward the eye from a line two inches from 
the extreme of its circumference. Then we began to hear about rigid 
spindle mills; mills whose grinding surfaces were a fixed and controllable 
distance apart; mills so arranged that there could be no possible oscil¬ 
lation of the runner. This represented the perfection of the idea, though 
it was never realized on a large buhr. 

As the grinding became higher and the products of middlings became 
larger, owing to the high grinding and the improvements in method, it 
became necessary to take measures to care for certain grades of stock 
other than middlings which were developed through the purifier, namely: 
germ, tailings and dustings. The smooth rolls took their place at this 
stage of the process and added to the machinery already used in the 
mill. Accompanying them, of course, were the reels, and as an offal 
from these reels, which the prudent miller did not care to run into his 
feed pile, there was the red-dog stock, which was taken care of by mill¬ 
stones and following reel or reels. In a mill which formerly contained only 
its millstones for the reduction of wheat and a reel or two for the separa- 


28 GRADUAL REDUCTION MILLING. 

tion of the flour there was added, consequent upon the introduction of 
the purifier, first, a buhr for cleaning the bran, one or two besides for the 
reduction of the middlings, two or three pairs of rolls for the reduction 
of the tailings, germ, dustings, etc., and finally a red-dog stone. Fol¬ 
lowing each reduction there were the reels. The great change is here 
made apparent. The limit of possibilities in the production of mid¬ 
dlings by the millstones was reached. The rigid spindle mill was the 
last step previous to the roller system. As we said, the idea of the 
rigid spindle mill was a reduction machine with its grinding surfaces a 
fixed and controllable distance apart. The rolls were the offshoot of this 
idea. In them were realized the desirable features of such amachine. Grad~ 
ual reduction existed in new process milling by millstones as a necessity. 
The middlings, the bran and other products required additional reduc¬ 
tion. Gradual reduction, as applied to the making of middlings by 
corrugated rolls in the roller process, was a principle as broad in its 
application to reduction as was the purifier in its original application to 
separations. Thus we have the purifier, not only as a revolutionizer of 
separations, but of reductions as well. We have the purifier, first, as a 
machine which took care of a product of old process milling, and which 
ultimately revolutionized it. Then we have the rolls and millstones 
forming a gradual reduction system to take care of the materials brought 
into existence by the purifier; and finally, we have this same gradual re¬ 
duction method as a revolutionizing element in new process milling. 
Gradual reduction, while it was formerly applied only to the intermedi¬ 
ate products following the original reduction of the wheat by the buhrs y 
with the rolls became part and parcel of what is now recognized as the 
gradual reduction system. With the introduction of this method we 
recognize different classifications requiring distinct reductions and as 
many separations. In later years this system of gradual reduction has 
been carried still farther, in the reduction from large to small mid¬ 
dlings, in the reduction from middlings of such a size as still contain 
attached to or as part of them certain objectionable impurities, to a size 
which admits of the removal of certain portions of this material. This 
process of the gradual reduction of middlings is carried as far as the 
limits of their purification by the ordinary machines will allow. As 
following out and adding to the machinery of purification which has 
always been the path of progress in milling affairs, the smooth rolls have 
come to be regarded as part of the purification machinery, and, as suchr 


GRADUAL REDUCTION MILLING. 29 

are legitimately regarded not only as reduction machines but as purifiers 
as well. This is the last step in the classification of the steps of milling 
progress. It is clear that the sole purpose of all changes in reduction 
methods since the introduction of the purifier has been with reference 
to increased production, in the first place, and increased purity in the 
second. 


CHAPTER III. 


THE UNDERLYING PRINCIPLES OF MILLING METHODS-THE PURPOSES OF 

WHEAT MILLING-WHEAT CLEANING AS A PURIFYING PROCESS-THE 

MIDDLINGS PURIFIER AS A BROKEN WHEAT CLEANER-THE REASON FOR 

THE PURIFICATON OF MIDDLINGS-REDUCTION FOR THE PURPOSE OF 

PURIFICATION—PURIFICATION FOR THE PURPOSE OF FURTHER REDUC¬ 
TION-GRADUAL REDUCTION AND GRADUAL PURIFICATION OF MID¬ 

DLINGS. 

In considering the various details of milling, I do not remember hav¬ 
ing noticed any attempt to show up the broad underlying principles ot 
milling as it is now carried on. 

The purpose of milling wheat is to get it into such shape that it can 
be made into bread, the idea being to get the most money out of it, and 
the process of so doing is to make the most dour possible out of the 
wheat and of a quality which will make the most bread out of the flour. 
It so happens that the most bread can be made out of the purest flour, 
the purity of anything being always estimated with reference to its com¬ 
plete fitness for the purpose for which it is intended. A thing might be 
spoken of as pure for one purpose when it would be impure for an¬ 
other. The best bread is that which is best to eat, and the best flour is 
that which will make the best bread, and the most of it, out of a given 
quantity of wheat. Now, if pure flour makes the best bread, the means 
of making pure flour is the logical sequence in this consideration. It is 
a question of process and the machinery to bring about that process 
automatically and economically. As to the process, and as a part of 
the desired end, reduction is the first great step and separation the 
second. Purification is the controlling idea as to the quality of the pro¬ 
duct. Reduction is a necessity in order to get wheat into flour form, 
and the success of the purification is the value-giving element. 

Where the cleaning of the wheat has to do with the removal of im¬ 
purities which are a part of it, it belongs to the purifying process. If 
we could thoroughly purify wheat, if its impurities were all on the out¬ 
side, we would never have had the middlings purifier in the first place, 


GRADUAL REDUCTION MILLING. 


3 1 


or gradual reduction in the second, or bolting machinery either, only in 
so far as it was desirable to grade the reduced material—a necessity 
brought about by incomplete reduction. If such a thing could have 
been done, such machinery would have been entirely unnecessary, ex¬ 
cepting as developed by incomplete reduction devices. The fact that 
there are particles of material scattered throughout the grain of wheat 
which are deleterious to the bread-making qualities of the Hour, was 
what developed the necessity for the middlings purifier, as a purifier of 
broken wheat. It was for the purpose of purifying the wheat that the 
middlings purifier was invented, and it was for the purpose of making 
more stock which could be purified, that is, middlings, that the system of 
gradual reduction was arranged. In the sense that a middlings purifier 
is intended for broken wheat, it is desirable that a large proportion of 
the stock should be maintained in this form rather than in the finer par¬ 
ticles known as flour. The reason that middlings can be purified and 
flour cannot, commercially, is clear when the principles of the purifica¬ 
tion of middlings are stated. The impurities in middlings are either 
larger in size, less in specific gravity, or different in structure from the 
desirable portion. In event of the impurities being larger, they may 
be separated from the middlings by bolting cloth. In event of their 
being of less specific gravity, air currents are arranged so that the lighter 
particles may be sent in one direction, while the middlings take their 
natural course in another. 

The separation, according to difference of structure, is made by rolls. 
For instance, germ may be flattened, while the middlings will be broken, 
or a piece of bran may pass through smooth rolls intact, while the mid¬ 
dlings, which are of the same size as the bran, would be broken into 
several pieces. By such an operation, the question of separation be¬ 
comes merely one which has to do with the size of the impurities. The 
germ and bran thus being larger than the middlings with which they are 
mixed, are readily separated by bolting cloth, as before stated. 

It is said that middlings are made in order to purify the wheat, and 
for the reason that the impurities thereof are not all external. It does 
not follow that the wheat can be purified by the mere reduction to mid¬ 
dlings, and their treatment as such by the purifying agencies mentioned, 
but it does follow that the fracture of the wheat liberates certain of the 
contained impurities, and as there are impurities contained in the unre¬ 
duced middlings themselves, which would get into the flour by the im- 


3 2 


GRADUAL REDUCTION MILLING. 


mediate reduction of the middlings after their handling by the purifiers, 
it follows that the gradual reduction of the middlings is as necessary as 
is the gradual reduction of the wheat. As this gradual reduction con¬ 
tinues, so does the purification. Gradual reduction and purification go 
hand in hand. It is gradual reduction and gradual purification. This 
is milling, and anything less complete is, in the same degree, incom¬ 
plete milling. 

There comes a point in the gradual reduction of wheat when we can 
no longer take off middlings of such a size as to commercially purify 
them. It then remains to take off all the flour remaining on the bran. 
In the process of making middlings, certain particles of the wheat and 
of the contained and other impurities are broken into such fine pieces 
that they cannot be treated by the purifying agencies outlined. It re¬ 
mains to handle such material on reels, taking out such a part as is 
known as flour, and making a separation of stock which may be desig¬ 
nated as dust middlings, they being between middlings and flour. The 
purity of this stock may be very much enhanced by the action of the 
smooth rolls, which reduce the middlings or flour particles, and either 
flatten or do not disturb the impurities. In this sense the smooth rolls 
and the following reels are purifiers, in that they remove a portion of 
the impurities. 

The same thing happens in the gradual reduction of middlings, though in 
that instance there is less effort to prevent the production of flour. But 
at the same time its production is gradual, in order that the middlings may 
be of such a size as to admit of purification and other reductions. Mill¬ 
ing is a process of reduction and purification, and in order that the puri¬ 
fication may be more perfect, the reduction and purification must be 
gradual. The reduction of the wheat has in view the production of 
middlings for purification. The gradual reduction of middlings has in 
view their gradual purification in order that it may be more complete. 
It is more complete by being more gradual, because there are contained 
impurities in the middlings which are liberated or detached with each 
reduction. 

Which system of the gradual reduction of wheat is the best? That 
system which will make the most middlings, the least flour, and, ulti¬ 
mately, the cleanest bran. Which system of the gradual reduction of 
middlings is the best? The system which will break the middlings, and 
at the same time cause the least disturbance to the impurities, leaving 
them in a separable condition acccording to one of the three conditions 
previously named. 


CHAPTER IV. 


DEVELOPMENT OF SEPARATING MACHINERY-SYSTEM OF SEPARATIONS HAS 

CHANGED WITH THE SYSTEM OF REDUCTIONS-MECHANICAL IMPROVE¬ 
MENTS IN BOLTING MACHINERY-THE CENTRIFUGAL REEL. 

We are accustomed to think of the changes in milling as having par¬ 
ticularly to do with the reductions and purifications by the purifiers. 
We are inclined to ignore the fact that changes in bolting and in all sep¬ 
arations, independent of the purifiers, have been as great and as import¬ 
ant as those having to do with the other methods. 

It is true that up to two years or more ago very few changes were 
made in the machinery of bolting, but if we ignore the fact that such 
changes and improvements have been made in recent years, even then 
it is clear that in the advancement, the bolting arrangements have kept 
pace with other details of the mill. The fact that a change has been 
made independent of the improvements in the machinery of bolting in 
itself, suggests that such a change must be in the system and arrange¬ 
ment of parts. 

As now arranged, the idea is not merely to separate the fine from the 
coarse stock in an abrupt way, but to make such separations according 
to principles and ideas which will not only remove the coarse particles 
of bran from the Hour, but also the fibre and soft matter, material of the 
same size as the Hour particles, and in fact remove to a greater extent 
than ever before, all of the impurities of the wheat, independent of their 
relation as to size to the flour and middlings particles. 

In former times the miller ran his chop from the stones into their 
reels, and commenced taking off flour at once. Generally there were 
not more than two reels. Flour was taken off from both. The bran 
and flour stock which did not pass through with the flour stock of the 
upper reel would tail into the one next below. After all of the flour 
had been taken out, the middlings and shorts were removed and finally 
(2) 


34 


GRADUAL REDUCTION MILLING. 


the bran tailed off at the end of the bottom reel. Of course there were 
cases where there was a single reel, but the same general principle was 
carried out. 

Now the miller will notice how great has been the change in the prin¬ 
ciple of separation. While in the instance just mentioned Hour was 
taken off first, middlings and shorts next, and the bran tailed off at the 
last, the correct thing to do, according to present practice, is to exactly 
reverse this order of proceedings. First, remove the bran, then the 
middlings and then make the Hour separations. It is clear that a change 
could be no more complete. 

In the millstone mills operating under the new process idea the bran 
was first scalped out on a scalping reel; that is, this was done in the 
more complete and better arranged mills, and then the coarse middlings 
were removed, and before the final Hour separations were made, the fine 
middlings were taken out. 

In the case of the millstone separations, it is necessary that a certain 
portion of the fine middlings be retained in the reels in order to assist 
in bolting. But with the better class of mills as little of this sort of 
thing was done as was possible. A smaller proportion of middlings 
was retained for the sole purpose of preventing the reel from pasting 
or clogging. After the introduction of gradual reduction methods 
this principle was even more clearly marked than before, and developed 
into what is known as the scalping system, which applies not only to the 
scalping from one reduction to another, and the separation of the finer 
particles previous to the Hour separations, but has to do with and is ap¬ 
plied to the Hour separations themselves. 

This is illustrated when we remember the very common practice of 
putting scalping cloths on the tail of nearly all Hour reels, which is done 
with the idea of separating the impurities from the Hour stock at every 
opportunity, of reducing the proportion of such impurities which may 
continue through the course of the mill. It is only the very fine mid¬ 
dlings which will pass through an 8 or 9 cloth that are allowed to pass 
through the flour reels. 

There is a much smaller proportion of flour stock with the reduced 
material than in former years by the millstone method, and, at the same 
time, there is a smaller proportion of fine Hour, for which reasons there 
is less difficulty in bolting this stock and less reason for running mid¬ 
dlings with the flour. 


35 


GRADUAL REDUCTION MILLING. 

The fact that there are many mills which are not doing their bolting 
according to these principles does not disturb the theory of the general 
improvement and general change in the bolting system. It merely 
indicates that the owners of such mills are not living up to their 
opportunities. 

As apart from the changes in the system and arrangement of bolting 
machinery, there have been changes in the machinery itself. In the 
first place may be considered the changes in the construction of the 
ordinary reel. As now designed they look entirely different from the ma¬ 
chines of earlier times. Not only do they look different but they are 
different, and the changes have been not merely those of convenience 
to the miller, but of radical improvement in the character of the work 
which they will do. There are the improved feeding arrangements, the 
speck boxes or heads, improved tail boards, the double conveyors, 
arrangements for examining the stock as it passes from one reel to an¬ 
other, and finally the arrangement of the conveyors side by side which 
makes it possible for the miller to examine his Hour one slide at a time 
when it becomes necessary, and to do it with the utmost ease. Finis 
he can determine to a nicety just how much flour can be taken from the 
reel. There is no guess work—no estimate to be made of the general 
result by the general appearance of the Hour as it comes from the con¬ 
veyor. 

The centrifugal reel when introduced into this country, was hailed as 
something which would create a revolution, but it had none of the radi¬ 
cal elements in its principle. It was said that it would supersede all 
other bolting arrangements, but it did not and cannot do it. The intro¬ 
duction of this reel was merely an addition to the good things which we 
already had, and as such an addition, was an improvement. The proof 
of this is to be found in the fact that even those who had the com- 
pletest mil s, and added these centrifugal reels, did not find it possible to 
do away with any of the other bolting machinery of their mills. As said 
before, they had added the machinery to that they already had. Many 
of them took the Hour which they had already made and re-bolted it on 
the centrifugals; others prepared stock on the centrifugals to be re-bolted 
on the common reels. One thing which a ceivrifugal reel can do is 
to correct some of the evils of a too close reduction by smooth lolls. 
Again, a centrifugal reel will re-bolt flour or fine stock which could not 


3 6 


GRADUAL REDUCTION MILLING. 

be handled by ordinary arrangements. In this fact alone is its principal 
merit and determines its greatest usefulness. 

The Morse elevator bolt occupies a field, mechanically, of its own, 
though as a milling machine to all intents and purposes it belongs to the 
same category as the centrifugal. 

The Jonathan Mills reel promises well, but cannot be considered at 
this time because of its recent introduction. 


CHAPTER V. 


THE DEVELOPMENT OF ROLLER MACHINERY-THE EARLY SMOOTH ROLLS 

-THE IMPROVEMENTS IN ROLLER MACHINERY-THE SIZES OF ROLLS 

MADE BY VARIOUS MANUFACTURERS. 

The first use to which rolls were put in this country was to the crush¬ 
ing of wheat. 

This crushing of the wheat was favored and practiced by many millers. 
As to how much good was accomplished by such an operation was never 
fully determined. It certainly did no harm. The bran was not dis¬ 
turbed or broken to a damaging extent, nor was the form of the wheat 
changed in such a manner as to operate unfavorably upon it during the 
course of its reduction by millstones. 

These rolls were very clumsy contrivances; many of them were as 
large as eighteen inches in diameter, and from thirty-six to forty inches 
in length, and the adjustments were frequently made by a monkey- 
wrench only. The rolls themselves were of ordinary cast iron, not 
chilled. After being run for a time they became pitted and irregular 
and uneven in form. Very early in the history of this process granite, 
stone and marble were used. 

After a time, however, smooth rolls came into use for the purpose of 
making a germ separation. These were chilled iron rolls. After this 
such rolls were used for making wheat reductions in the manner above 
described, and the stone and cast-iron rolls were discarded. The me¬ 
chanical arrangement of these chilled iron rolls, as first used, was about 
as clumsy and ordinary as could be devised. The process of leveling 
them or keeping them in line with each other was a matter of great 
difficulty. It was usually done by adjusting them and then running the 
boxes to suit. Then these boxes were difficult to lubricate, and as for 
keeping the frames clean, that was out of the question. 

The frames were usually of wood, heavy and ponderous. Arrange¬ 
ments for adjusting were primitive indeed. There was the hand-wheel 
of the ordinary form without spring or tension attachment, and between 
the two boxes, on either side, was a round stick with a piece of rubber 


38 


GRADUAL REDUCTION MI LUNG. 

on each end which was intended to throw the rolls apart when the hand- 
wheel compression was released. When the belt happened to puli in 
the wrong direction the rolls never could be open at both ends. 

The arrangements for inspecting the stock which passed through these 
rolls clearly indicated that it was rarely done. In the first place the rolls 
sat too close to the door, and then the opening was nothing more than 
a round hand-hole in the hopper under the frame, and when opened 
would cause the dour to drop to the door. A large number of such 
machines were in use during the whole period of new process millstone 
milling. During the latter part of this period, however, other more 
suitable and better contrived arrangements of rolls were put into use. 
For the most part they were cast-iron frames arranged for a single pair 
of rolls, with journal-boxes of brass and babbitt linings—a more intelli¬ 
gent construction than those of the earlier period. Arrangements for 
adjusting were a little better than the ordinary arrangements. In truth, 
at this time very little attention was usually paid to the adjustment of 
rolls. When the mill started they were set up tight, and when it was 
stopped they were opened out, one end at a time, with the hand-wheel. 
It was not an unusual thing to see a pair of rolls set up by grasping the 
hand-wheel with a monkey-wrench so as to get a good purchase on it. 
Of course the stock which passed through such rolls was mostly dakes, 
and in order to get rid of ihese dakes it was run through a bran duster, 
which destroyed all the purifying effect of a roller reduction. This con¬ 
dition of things was quite common after rolls came to be used for other 
purposes than germ reductions. For instance, on dustings, returns, etc. 

The great change in roller machines was made immediately upon the 
introduction of corrugated rolls for reducing the wheat. These changes 
were made by the suggestions offered by the imported rolls. They were 
of very superior construction. Our people were quick to recognize the 
necessity for more perfect arrangements, as gradual reduction made it 
imperative. Prompted by the example set us by our foreign neighbors, 
our mill builders immediately set about to give the millers a better roller 
machine, and to-day the American miller certainly has the mo^t con¬ 
venient and ingenious arrangement of roller reduction machines to be 
found anywhere in the milling world. As to excellence of workmanship 
they are certainly equal to the demand. 

From rolls of thirty and thirty-six inches in length and ten and twelve 
inches in diameter, a change was made immediately after the time of the 


GRADUAL REDUCTION MILLING. 


39 


changes in reduction methods to eighteen inches in length and nine 
inches in diameter. Now we have machines that are much smaller in 
every way, for the purpose of adjusting the size to the requirements of 
small mills. However, 9x18 more nearly approaches the standard size 
than anything else that can be called to mind Twenty-four-inch rolls 
are still used, but thirty-inch machines are not recommended by the best 
or most successful mill builders. 

1 he belt drive was one of the innovations and was received with ap¬ 
proval by most of the millers of this country. All, however, did not 
use the countershaft device for driving the slow roll, substituting instead 
a cross belt connection with the main line shaft. 

While a single pair of rolls was the common number for a frame, 
according to the earlier practice, two pairs of rolls to a frame has been 
the common and almost universal custom during the recent years. It 
has not only been more economical, but is more convenient as well. It 
makes possible a more perfect mechanical contrivance for driving and 
adjusting. 

Other details of arrangements and improvements which have been 
made upon roller machines are well understood, and as far as the writer 
knows there is not a roller machine on the market which will not 
do good work if intelligently handled. There are little differences of 
detail and small conveniences which may make one roll or another a 
favorite with various millers, but there are no roller machines that are 
not well adapted to doing good work under judicious management. 

The following are the sizes of rolls made by various manufacturers. 
Under this head is included both smooth and corrugated: 

EDW. P. ALLIS & CO., MILWAUKEE, WIS. 

Gray's Noiseless Belt Roller Mill —Standard style, 4-roll, 9x14, 9x18, 
9x24 and 9x30 inches; standard style, 4-roll, with Wegmann’s patent 
porcelain rolls, 9x14, 9x18 and 14x16 inches; style B, 4-roll, with smooth 
chilled iron rolls, 9x8, 9x11 and 9x14 inches; style C, 9x8, 9x11, 9x14, 
9x18, 9x24 and 9x30 inches. Four-break reduction machine, No. 1, 6x6 
and 6x8 inches; No. 2, 9x8 and 9x12 inches. Double or 4-roll ma¬ 
chines, 6x12, 6x16 and 6x20 inches. 

STILWELL & BIERCE MANUFACTURING CO., DAYTON, O. 

Odell's Patent Noiseless Roller Mill— Standard style, double and 
single, 9x18, 9x24 and 9x30 inches, also 10x24 and 10x30 inches in ex- 


40 


GRADUAL REDUCTION MILLING. 


tra heavy frames; style C, 4-roll, 7x14, 7x16, 7x18 and 7x20 inches; 
quadruple, 8-roll, 7x14, 7x16 and 7x18 inches; style D, 4-roll, 7x14 
inches; concentrated mills, 2, 3, 4, 5 and 6 breaks, 9x18, 9x24 and 9x30 
inches. 

THE JOHN T. NOYE MANUFACTURING CO., BUFFALO, N. Y. 

Stevens Roller Mill. —Single, 6x12, 6x15, 6x20, 9x15, 9x18, 9x24 and 
9x30 inches; double, 6x12, 6x15, 6x20, 9x15, 9x18, 9x24 and 9x30 
inches. 

Cosgrove Concentrated Roller Mill. —Five-break machines, 9x15, 
9x18, 9x24 and 9x30 inches. 

Rounds Sectional Roller Mill. —Two, three or four breaks, with 
cylinder scalpers, 9x24 and 9x30 inches; also same without scalpers. 

STOUT, MILLS & TEMPLE, DAYTON, O. 

Livingston Belted Roller Mill. —Double or single mills, 9x12, 9x15, 
9x18, 9x24 and 9x30 inches. 

Gilbert Combination Mill. —Four or six-break mills, 9x12, 9x15, 
9x18, 9x24 and 9x30 inches. 

Eight-Roller Universal Mill. —6x9, 6x12, 6x15 and 6x18 inches. 
Also 4-roller mills same sizes. 

NORDYKE & MARMON CO., INDIANAPOLIS, IND. 

Size of Rolls. —Single, 9x18, 9x24 and 9x30 inches; double, 6x12, 
7x14, 7x18, 9x18, 9x24 and 9x30 inches. 

CASE MANUFACTURING CO., COLUMBUS, O. 

Bis?narck Roller Mill. —6x12, 6x18, 9x18, 9x24 and 9x30. 

GRISCOM & CO. & M’FEELY, PHILADELPHIA, PA. 

Butler Roller Mills. —9x18, 6x12, 6x16 and 6x20 inches. 

BARNARD & LEAS MANUFACTURING CO., MOLINE, ILL. 

Daverio Three-High Roller Mill. —6x12, 6x15, 9x18 and 9x24 inches. 

TODDS & STANLEY MILL FURNISHING CO., ST. LOUIS, MO. 

Four-Roller Mill. —7x14 and 9x18 inches. 

JOHN JAMES & CO., LA CROSSE, WIS. 

La Crosse Smooth Chilled Lron Roller Mill. —Single, 5x10, 6x12, 6x15, 
6x18, 9x12, 7x16 and 9x18 inches; double, 5 xio, 6x12, 6x15 and 6x18 
inches. 


GRADUAL REDUCTION MILLING. 


41 


DOWNTON MANUFACTURING CO., ST. LOUIS, MO. 

Cransoti-Dawson Patent Roller Mill. —Single, 9x18, 9x24 and 9x30 
inches; double, 9x18, 9x24 and 9x30 inches. 

W. H. BARBER & CO., ALLENTOWN, PA. 

A. N. Wolf Pate?it Noiseless Roller Mill. —Two-roller, 4-roller and 
8-roller mills, 7x14 and 9x18 inches. 

ELI STRONG, KALAMAZOO, MICH. 

Strong l^atent Roller Mill. —9x18, 9x24, 7x12, 7x15 and 7x18 inches. 

FARMER ROLLER MILL CO., GRAND RAPIDS, MICH. 

Fox Patent Roller Mill. —Single, 6x12, 6x16 and 6x20 inches; double, 
6x12, 6x16 and 6x20 inches. 

PHCENIX IRON WORKS CO., MINNEAPOLIS, MINN. 

Monitor Roller Mill. —No. 2, 6x12; No. 3, 6x15; No. 4, 6x18 inches. 

Little Monitor. —No. 2, 6x10; No. 3, 6x12 inches. 

RICKERSON ROLLER MILL CO., GRAND RAPIDS, MICH. 

Rickerson Patent Noiseless Roller Mill. —6x12, 6x15, 6x18 and 6x20 
inches. 

NORTH STAR IRON WORKS CO., MINNEAPOLIS, MINN. 

Fir Roller Mill. —Double, 9x18 inches. 

WILLFORD & NORTHWAY MANUFACTURING CO., MINNEAPOLIS, MINN. 

Noiseless Belt Roller Mill. —Single, 6x12, 6x15 and 6x20 inches; 
double, 6x12, 6x15, 6x20, 9x14, 9x18 and 9x24 inches. 


CHAPTER VI 


DEVELOPMENT OF MACHINERY FOR SMALL MILLS-THE COMBINATION 

* 

MILLS-PRINCIPLE OF THEIR CONSTRUCTION-SUGGESTIONS AS TO 

CHANGES-CONSOLIDATION A NECESSITY IN SMALL MILLS-THE DISC 

MILL AND ITS DEVELOPMENT. 

After the large mills got their start, the small millers began to look 
around to see what they should do to keep up with the improvements, the 
expense of such mills being one element in the problem which received 
serious attention. The first thing done was to build a roll frame with 
a scalping reel immediately under it. Most of this frame was of wood, 
and the reel was a little over two feet long. A millwright, on being asked 
if he did not think that this was too short, said no, that if the stock was 
not well dusted when it went to the next reduction, that coarser cloth 
could be put on the reel. A certain local millwright was quite enthu¬ 
siastic about this machine, and honestly so. He had a plan in which 
he proposed to get a four-break null in on two floors without the use 
of elevators to carry the stock from one scalper to another, his idea be¬ 
ing to build a platform on each floor and in that way have the rolls 
placed on four different levels. Thus the first break rolls, which would 

be on the platform located on the second floor would tail off to the 

• 

second break rolls immediately below this platform on the floor proper, 
and from that to the third break located on a platform on the first floor, 
then to the finishing rolls which were immediately under. The product 
of the scalping reels he intended to run to an elevator. This thing 
was probably never done, but was the germ idea of the combined roller 
mill which followed. 

\ 

The combined roller mill, the one which combines rolls and scalpers 
all in one frame and driven by the same belt, was the most promising 
of the steps made in the direction of the decrease of the expense of 
building small mills. The first combined mill was the one with brush 
scalpers, and was launched forth with a good deal of enthusiasm, and 
not without reason, for it has since met with a degree of success. If 
memory is not at fault, this mill was first operated at Faribault, Minn. 


GRADUAL REDUCTION MILLING. 


43 


In any event, it was in one of these towns connected with the early his¬ 
tory of the purifier. An article appeared in a local paper in which the 
enthusiasm and zeal of the writer would have the public believe that 
this invention was on a par with the purifier, and exhibited a good deal 
of pride that two such machines should have emanated from the same 
town. 1 here will be occasion to refer to this machine again, for whereas 
it was the first machine put on the market, it is still one of the best. 
Other combination machines followed, in just what connection is not 
known, but there was one in an iron frame which had scalping reels of 
the ordinary type following each pair of rolls. The frame was built in 
sections containing one reduction each, and by placing one section on 
top of another any number of reductions desired could be had. This 
machine never came into very general use, but some of them were sold 
and are still operating. 

A combination machine which came out about this time had sieve 
scalpers of peculiar construction. This, too, met with a moderate de¬ 
gree of success. One thing about this machine was that it was not too 
high, it being possible to get a six-break mill all on one floor. These 
combination machines rarely have more than five breaks, however. 

The Seek combination mill was probably brought to this country be¬ 
fore either of the two latter machines were in operation. It is not known to 
the writer that it ever passed beyond the experimental stage, though it was 
very favorably reported on from Minneapolis. This machine contained 
a very ingenious device for conveying the stock from the roll discharge 
to the reel, both of which were on the same level. 

One of the most novel arrangements for gradual reduction for small 
mills is a device which makes three or four breaks with one pair of rolls, 
which are divided into sections for the various breaks, each section 
varying in length, diameter and fineness of corrugation. The increase 
in diameter, section by section, makes it possible to gradually come down 
on the stock as the reductions progress. For instance, the section which 
accomplishes the first break is the smallest, hence the grinding surfaces 
are farther apart. The next section is a little larger, and so on to the 
finish. There are short elevators for transferring the unreduced material 
from one section to another. 

One of the latest combination machines is for four breaks. The rolls 
are all on one level and are inclosed within one frame, which is of wood, 
the pairs of rolls being so placed that one pair comes at each corner of 


44 


GRADUAL REDUCTION MILLING. 

the frame. The scalpers are immediately under the rolls. '1 hey tail 
toward the middle of the frame, where room is left for elevators which 
carry stock from the tail of one reel to the hopper of the next roller re¬ 
duction. This machine occupies less space in height than any of the 
others, unless it be the last mentioned, but more floor space, which, 
however, is not great. This is a complete belt drive machine. 

In the opinion of the writer there is one fault common to all combi¬ 
nation machines, and that is the unvarying length of the scalpers. A 
scalper which is long enough for the last break is too long for the first 
ones, or if it is the proper length for the first breaks it is too short for 
the last. We all know that it is absolutely necessary, in order to carry 
out the principles of gradual reduction, that all of the Hour and mid¬ 
dlings made on one reduction should be taken out before it passes to 
the next. It is also a matter of knowledge that the scalpers should not 
be too long, that the stock should not be whipped around in a reel 
when there is nothing in it which can be properly taken out, but which, 
in the nature of things, will cause a dangerous proportion of small red 
bran stock to be run into the reel product of better material. This> 
however, is hardly a fault of the scalpers of the combination machines. 
They are more often too short than too long on all breaks except, 
perhaps, the first and second. The first combination machine made got 
over this difficulty better than any of the others by using brush scalp¬ 
ers, that is, scalpers with brushes on the inside. Brushes, however, do 
not seem to be exactly the thing for a scalper, as the tendency is to 
pulverize the stock. One way to get out of the difficulty of properly 
scalping the stock on the middle and last breaks is by using centrifugal 
scalpers, though they are not so good as the common reels of the proper 
length. 

A combination mill might be made which would obviate all of the 
difficulties mentioned. With the first and second breaks, is suggested the 
use of the reels as ordinarily made. When it comes to the third break 
a centrifugal might be used, but of a type not so severe as those in ordi¬ 
nary use, being as mild in its performance as possible to keep the cloth 
open. The fourth break scalper would be a centrifugal of a more pro¬ 
nounced severity in its movement and beater qualities. The fifth, if it 
be the last break, should be of the ordinary centrifugal type, which 
would give a clean tail over the tail of the reel. By such an arrange¬ 
ment there would be scalpers of an uniform length, say four or five feet, 


GRADUAL REDUCTION MILLING. 


45 


but of increasing severity from the first to the last breaks. This is all 
that is wanted to make a combination machine a success. It is the 
lack of such an arrangement which has caused trouble in times past. 

Smooth rolls of short length and small diameter are now being made 
for small mills. The time was when a small miller had to buy the same 
sized smooth roll which was ordinarily used in large mills, and if he did 
not have the proper quantity of stock to run on this roll of a par¬ 
ticular class, he ran other stock to it to make up the volume. Regular 
practice of this kind developed a habit, early in the days of gradual re¬ 
duction milling, which leaves its mark on the mills of to-day. That 
habit was to run conglomerates on the rolls. By this is meant stock 
of different kinds, fine and coarse, bran and white stock. It is as diffi¬ 
cult to reduce fine and coarse stock together on the same roll as it can 
be to do anything which was never done before. The introduction of 
smooth rolls of small size opens a way for a change in the old habits. 
There are smooth rolls which are arranged immediately over a reel frame, 
that is the roll and reel are together and form a combination machine. 

It must certainly be a very agreeable arrangement for many mills, saving 
* 

expense in that it dispenses with an elevator quite often, but more than all 
consolidates the machinery. The millers of these small mills have so 
much more to do than they can do to the best advantage, that it is 
pleasing to notice any changes of this kind which will lighten their bur¬ 
dens. In the old days of stone milling when a miller had one or two 
pairs of buhrs, perhaps, and one or two reels and the cleaning machinery 
to take care of, it was possible for him to devote attention to the 
customers; to help unload and weigh the wheat; to do all of the sweep¬ 
ing and take care of the mill, without doing himself an injustice. But 
since that time there has been a constant addition to the machinery 
which requires constant and increasing care and attention from the 
miller without a corresponding diminution of the amount of outside 
work required of him. 

Anything which leads to a consolidation, to a drawing together and 
simplification of milling machinery, is to be looked upon as a positive 
improvement in milling methods. Not but that as good work can be 
done without the combination, but that the work will be better done 
where there is such an arrangement. Where there is scattered machinery 
which extends over two or three fioors and with a wide distribution on each, 
and taken in connection with the fact that the miller has so much irreg- 


46 


GRADUAL REDUCTION MILLING. 

ular work to do which divides his time and attention, he cannot get good 
work—uniform work—out of his mill. If the machinery arranged in 
combination form were even not so good for milling purposes, the results 
would be better on account of the care and attention which it might re¬ 
ceive by the lightening of the labor. 

There seems to be no way of solving the problem of gradual reduction 
for small mills except through the means of combinations and consoli¬ 
dations. Combination mills are not as popular as the other arrange¬ 
ments, because of prejudice built up against them on account of the 
lack of complete success of combination break mills, but the way has 
been pointed out in which this difficulty will be eventually met. 

Disc mills, which do good service on the first break, have been largely 
made and marketed for small mills. One great reason why they have 
not been generally used has been on account of what was supposed to 
be the mechanical troubles attending their operation. They were always 
getting out of adjustment, getting hot in the neck and otherwise causing 
trouble. At the same time that this was so, there are few pieces of 
machinery which have been put into a mill which were more carefully 
designed or better made. The whole trouble has been owing to the ex¬ 
travagant claims of capacity made by their designers. This is particu¬ 
larly true where these machines have been put into large mills, and be¬ 
cause there was not so much for them to do, has been the cause of their 
greater popularity in such mills. Take, as an example, a prominent 
disc reduction machine. Somebody was anxious to build large mills 
with a small amount of machinery. We all remember how hot the chop 
came from these mills on the middle and last breaks. There was no 
reason for this other than overcrowding. A disc mill for the size spoken 
of does not rightly or naturally have any more capacity than a single 
pair of 9x30 rolls, but the fact is that anywhere from three to five times 
as much stock was forced through them by high speed. Experience 
with a millstone led to the belief that a high speed and a heavy feed 
were two things which we did not want, yet after arriving at the perfec¬ 
tion of millstone work by slow speed and a light feed, the disc mill was 
devised and we went to the other extreme of over-grinding, overcrowd¬ 
ing. A disc mill is nothing more or less than the perfection of the mill¬ 
stone idea. It is the degradation of the millstone idea to take a perfect 
machine and kill it by overwork. 


CHAPTER VII. 


INVESTMENTS IN MILLS-THE PRODUCTION OF CHEAP FLOUR—OVERRATED 

MILLING CAPACITY-A SYSTEM OF MILLING WHICH MAKES MONEY. 

Capitalists sometimes hesitate to invest money in mills because of the 
past uncertainty of milling affairs as applied to systems of manufacture. 
It is only within the past year that the majority of millers would believe 
in a stable condition of things. 

At this time there is less interest of an excitable nature, less interest 
brought about by uncertainty in milling affairs than formerly. Most 
millers understand well the work which they have in hand; understand 
what they are doing at present, and, what is more interesting, feel as¬ 
sured that the doings of the future cannot be widely different from the 
work of the present. The knowledge that it was possible to purify 
middlings brought about more than ten years of hard work, and com¬ 
pletely revolutionized the system of milling. It has taken these ten 
years or more to work out the details of a system which had its root in the 
idea of a purifier. This time of which we speak has been wholly taken up 
with the idea of purification. The work may have apparently diverged 
from that point, but there has always been a clear connecting line, no 
matter how great the divergence. The purifier improved the millstone 
work. Its efforts were to get the most middlings by means of the mill¬ 
stone. The purifier discarded the millstone and supplanted it with the 
roller system of gradual reduction, and it will favor any system or any 
detail which will make more or better middlings than any other system 
or detail. The matter of purification controls the introduction of new 
machinery. It will decide whether or not the roller system of gradual 
reduction will keep its place. The indications are that the minds of 
people have settled down to the fact that there is nothing better in sight 
for making middlings than the system now in use. This is a general 
and common feeling among millers and men engaged in manufacturing 
milling machinery. It is a feeling which is opposed to the restlessness 
of times past. It has had its quieting effect upon the present, as it 
will continue to have in the future. The fact that there has been no 


48 


GRADUAL REDUCTION MILLING. 


reduction machinery which has been decidedly successful when com¬ 
pared with the rolls, is another thing that will serve to enforce an easier 
feeling on this subject. After the system of gradual reduction by rolls 
was established, there were continuous and strong efforts to supplant it 
by other means. This was the result of the impetus which the inventive 
spirit had received in the past. It had been set in motion, and it was 
difficult to stop, even after the goal had been reached. It was sliding 
past the station. 

Investing money in a mill is like investing it in rental property. Say 
one has eight or ten thousand dollars to invest, and he puts it in houses 
—small houses. Now, one man will make them as cheap as possible. 
They will be mere shells, barely keeping out the rain, but not the cold 
to any great extent. Another man builds about the same sized house, 
builds it reasonably well, adds a few of the conveniences to the interior, 
and altogether has a building which is quite habitable and somewhat 
attractive. Now, there would be times when the man who has the cheap 
house would get a larger return on his investment than he who has been 
somewhat attentive to the comfort of his tenants. But as soon as there 
comes about a little stringency in business matters, and there are vacant 
houses, the man with the very cheap house will be the first to suffer, 
while he who has done something better will retain his tenants upon a 
profitable basis. His houses will be among the last to be empty—in 
fact, as long as houses are rented at all, he will have his income. 

It is just so with milling matters. There are times when any kind of 
a mill will make money. There have been such times. But again there 
comes a change when only the fittest are known to prosper. In times 
of prosperity one miller has been known to say that he did not think it 
necessary to fill his mill full of machinery to make a little flour; that he 
was doing about as well as his neighbor, with two-thirds of the invest¬ 
ment. But when the commercial pinch is feit, the man with the two- 
thirds mill growls dreadfully, and says there is no money in milling. He 
cannot understand why his neighbor keeps moving along. He figures 
out a loss of twenty-five cents a barrel on every barrel of flour he is 
making. But the neighbor still moves along. He runs full six days and 
a half in the week, and it is known that he has orders four and six weeks 
ahead. But the two-thirds man does not understand it—says milling is not 
what it used to be, and he recalls and lives on the time when he made a 
dollar a barrel. The fact is, he is neither making his flour so good nor 


GRADUAL REDUCTION MILLING. 


49 


so cheap as the miller who is more prosperous. He has neither the ma¬ 
chinery nor the mill with which to do it. 

There are in mind at this time several instances of the kind which I here 
mention. One mill, in particular, is recalled, which haS three times as 
much machinery to make a given quantity of flour as is being used in 
many other mills. It is known that this miller is getting, on an average, a 
dollar a barrel more for his patent flour than the regular market quota¬ 
tion on this grade. This does not indicate the exact difference in his 
receipts for the same quality of flour as compared with that of some 
other millers, as he is making his flour cheaper, that is, using less stock 
than is common with the majority of millers. He is not only making 
his flour better, but is making it cheaper. He is cutting profits on both 
ends of the string. Now, how does he do it? In the first place, he 
cleans his wheat, and he does it slowly. He does not operate on the 
full advertised capacity of the machines for a twenty-four hour run, and 
then do all the work in twelve hours. He runs his cleaning machines 
below what would be considered the ordinary rating of capacity, and, 
as he has not enough machinery to clean his wheat in a few hours, he 
keeps it going all the time, and he has enough help so that it can be 
properly watched—watched not only as to the quality of the work done, 
but as to the waste in cleaning his wheat. 

Now, we all know of instances where the miller who has wheat to 
clean, periodically starts his cleaning machinery, runs it two or three 
hours and fills up his bins. In many such instances the machines have 
one-half to one-third more work to do than their advertised capacity, 
which latter is more than they are capable of doing to the best advant¬ 
age. In the cry for machines of large capacity, the makers have been 
forced to advertise the maximum amount which can be done by their 
machines; hence, when they are crowded beyond this point, it is disas¬ 
trous to good milling. Let him who reads this look about him and 
think how few very good mills there are into which he can go and take 
a handful of cleaned wheat out of the first reduction hoppers. And 
while he is casting his eye around among his neighbors’ mills, let him 
think of his own mill, that he may judge of the quality of the wheat 
cleaning there. 

It was said that this miller who is doing so well cleans his wheat. 
This being done, he reduces it, and reduces it properly. None of the 
machinery is overcrowded. He has from a fourth to a half more grind- 

( 4 ) 


5o 


GRADUAL REDUCTION MILLING. 


ing capacity than is common in nine mills in ten. Thus he is able to 
make round middlings, and a small proportion of break flour. The 
middlings are such as can be readily pulverized. The flour is such as 
contains a small proportion of pulverized bran. He does only at each 
reduction what properly belongs to that reduction. It is not a struggle 
to make the rolls take the stock, but an intelligent effort to have them 
take what they can and do it well. He has seven breaks on the wheat, 
and he has clean bran when he gets through. There is very little flour 
to be dusted from his middlings, hence they are well dusted. There is 
a small proportion of middlings with adhering portions of bran, there¬ 
fore they can be readily purified. These middlings are not simply cleaned 
on the machines and made to look bright, and reduced at once into flour, 
but, after being purified the first time, they are reduced lightly on smooth 
rolls. Flour is then taken out of them, and, by the way, this flour is of 
most excellent quality. Then the remaining middlings are purified 
again, and so on through a course of some seven or eight reductions, 
dustings and intermediate purifications. After the stock becomes too 
fine for purification on the machines, it is reduced on smooth rolls. 

This is a system which includes the gradual reduction of wheat and 
the gradual reduction and intermediate purification of the middlings. 
The gradual reduction of the wheat is not gradual alone in that it is done 
by a succession of operations, but gradual in that as little as possible is 
done at each operation. This is the idea of gradual reduction milling. 
There are those who would call it fancy milling, and again there are 
those who would say, if this thing were not in actual practice, that this 
kind of talk might be all well enough in theory, but it would not make 
money. The fact is that it does make money, and that the miller who 
handles his wheat in this way is getting more money per bushel out of 
it than any other miller in the country, as far as the writer knows. He 
is probably getting more profit per bushel of wheat from his milling than 
any one else in this country. The means which are used to do this 
thing the writer cannot but think are the best means. The miller who 
gets the most money out of the wheat is the best miller, and the method 
which he uses to do this thing is the best method. There is no way of 
getting around this statement. 

It is refreshing to know that no one can say of this miller that he is a 
mere theorizer—that he spends all of his money on his mill and that he 
has nothing to show for his investment. He is a money-maker, an ac¬ 
cumulator, an enthusiast in milling work, a practical man and an ex¬ 
tremist in all that he does. So far, his extreme methods have led him 
in the direction of extreme success. 





CHAPTER VIII. 


TROUBLES IN THE BAKING OF FLOUR-UNIFORMITY OF FLOUR COMPARED 

WITH UNIFORMITY IN ITS BAKING-THE DIFFICULTIES IN THE WAY OF 

THE UNIFORMITY OF FLOUR MANUFACTURE-CHANGES IN MILLS-THE 

EFFECT OF SUCH CHANGES IN THE MARKETING OF THE FLOUR. 

It has happened many times that the housewife, when taking the first 
baking of flour from the new barrel which has just arrived, would look on 
it with suspicion, as she does on all new things in general, and new flour 
in particular. As she is suspicious, she is inclined to find fault, and, if 
we look down into her thoughts, we find that she does not think that 
this flour looks quite as good as the last, and that it does not act the 
same, thus fortifying herself with an “I thought so” as an equivalent to 
“I told you so,” in event of failure. This is a splendid state of mind 
out of which to get a failure. It is anticipated. In many cases it so 
happens that the bread is not up to the family standard, and with the 
tale of woe she wends her way to the diplomatic miller, who induces her 
to try another baking, which frequently brings about a happier state of 
affairs, and after the third or fourth baking all troubles are forgotten. 
There is a story of a very good old lady, who prided herself on being a 
good judge of flour by the mere handling of it. Said she, “You just 
take a handful of it and throw it up against the wall and if it sticks, or 
if it don’t stick, I forget which, why it’s good flour.” All this is very 
satisfactory. 

Did it ever occur to the reader how much more uniform in quality is the 
flour than the bread which is made from it? If it were possible to view all 
the bakings of the average housewife from a single barrel of flour, the result 
would be appalling from a bread-making standpoint. Several times in 
my experience do I remember that I was in fear that lifelong friendships 
would be ruptured because a complainant felt so aggrieved over the fact 
that the last part of a barrel of flour was inferior to the other part. 

Considering the methods of the manufacture of flour, its intricacies, 
the delicacy of its demands, the imperativeness as to the results, we 



5 2 


GRADUAL REDUCTION MILLING. 


have reason to congratulate ourselves upon the general uniformity of the 
product. With all these things to be considered, I have in mind a 
milling firm which was ever ready to pay rebates and to make good all 
damages, and who did not have occasion, in a year’s business, where 
over 200,000 barrels of Hour were made, to meet any such demands. 
There are very few lines of manufacturing where the real difficulties of 
maintaining uniformity are so great, and, at the same time, there are 
very few lines where there is such exactness. In the mill there is a 
great deal done which no one sees. There is a constant moving on, a 
constant manufacture for better or for worse. Literally and figuratively, 
a great deal is done in the dark. One thing must be examined at a 
time. There is no place where the work, as a whole, may be taken into 
account, as may so readily be done in most other work. There are no 
opportunities for testing the work as a whole in a way to know that every 
thing is right at the moment. There is very little chance of forseeing 
difficulties or wrongs. More often than otherwise, changes in the opera¬ 
tion of the mill—in its grinding, in its bolting or its purifying—are not 
made until the necessity is apparent from the result. There are no 
“cut-and-try” methods, there are no patterns or templets, fixed methods 
or arbitrary rules. A mistake once made is made forever. It goes on 
through the mill. If a carpenter gets a board too long he cuts it off at 
his leisure. If a miller gets his bolting too long, he cuts it off, 
but with the knowledge that something has gone before which was not 
as it should be—a mistake which cannot be corrected. With a miller a 
mistake cannot be corrected until it is apparent and more or less dam¬ 
age has been done. By the result he judges as to the necessity for a 
change. The result which has gone before he cannot change. If a 
millwright gets anything wrong it is always possible to make such altera¬ 
tions as will not affect the other parts of his work or the general result. 
It is required of a miller that he be able to judge with the utmost accu¬ 
racy, to make close and fine distinctions as to the various results in the 
process of working out in the different parts of the mill. Thus his mind 
is trained in such a way as to recognize what appeared to him to be 
broad differences, while in fact, to the public, they are not noticeable. 

In making mechanical changes, either in principle or in detail, it often 
and generally happens that the grades of flour are changed, say improved. 
The patent may be better than before, and we will allow that the same 
may be true of the bakers’ or clear Hour. The low grade maybe worked 







GRADUAL REDUCTION MILLING. 


53 


down in quantity. It may be said that the product of the mill is im¬ 
proved. All this may be so and the miller not be benefited in the least. 
On the contrary, when he makes such changes and brings about such 
results, the chances are favorable to his being hurt if he does not handle 
his trade very skillfully. 1 he trouble, if any, generally comes about in 
this way. It will be allowed that previous to the time of making these 
alterations he had a trade for his Hour under brands owned by him¬ 
self or the trade, and at prices which fairly represented its value. 
Now the trade had the flour where that particular quality and price 
was wanted, and the general state of affairs, with them, was fairly satis¬ 
factory. The miller, desiring to get more money out of his wheat, 
improves his flour in the manner previously indicated. Realizing, as he 
does, that it is better than before, he wants more money for it. In truth, 
it is worth more, and he asks it from his buyers—they of the East and 
South. While they are willing to acknowledge that the flour is better, 
and that it is actually worth more money, the fact remains that they have 
built up the trade on the other grade—another flour. That whereas the 
flour was sold for $6 before, it is now a $6.50 flour in quality. But the 
$6.50 flour is not what the trade wants; they want a $6 flour, quality 
and price, for a $6 trade. When the grade is improved and the price 
raised, the flour has to go into new hands. The same jobbers may take 
it, but they have to put it into other hands. They have to build a new 
trade for a new flour, whether it comes from the same mill or another 
one. What if this jobber does say to his trade, which buys it in small 
lots from him, “This flour has improved; it is worth 25 cents a barrel 
more than it was before. ” And what if his buyer recognizes this as be¬ 
ing so? He will say: “I do not want it improved; it fills the place which 
I have for it, and at its price. ” All he wants is the uniform grade. He 
has, maybe, a $6.50 grade from another mill under an established brand, 
which is altogether satisfactory, and he is not going to change to another 
flour, fearing, as he does, that the grade may be changed again; and he 
is justified in this view of the case. .Consequently the trade for the 
old grade of flour is lost and has to be built up, and maybe at a time 
of the year when this is not easy to do. The illustration here given rep¬ 
resents a state of affairs which is not at all uncommon. Now, while the 
moral of all this is not that one should refrain from improving his mill¬ 
ing, it does suggest that it should be done understandingly, and with a 
view of meeting the dangers here referred to. A miller in Ohio who, 


54 


GRADUAL REDUCTION MILLING. 


while he has been improving his milling from time to time, has not ma¬ 
terially changed his grades since he adopted the gradual reduction sys¬ 
tem. His improvements consist in that he has gotten more dour out of 
the wheat, and has so separated it that the percentage of the lower 
grades has constantly decreased. But at the same time the quality has 
been approximately the same. This may not be the best way, but it 
is one good way. At any rate it is making money to-day. 



CHAPTER IX. 


THE EFFECT OF MILLERS CHANGING PLACES-CHANGES AND ALTERATIONS 

CAUSED THEREBY-THE EFFECT OF DIFFERENT MANAGEMENT OF THE 

SAME MILLS-THE CHANGES WHICH ARE TO BE MADE-THE TIME OF 

MONOPOLY AND HIGH GRADES PAST-CHEAP FLOUR THE FLOUR OF THE 

FUTURE. 

It is not an unusual thing for millers to change places. There are 
many reasons leading to this. Naturally enough it frequently happens 
because of the desire to do better. The mill owner, in some instances, 
may think it to his advantage to dispense with one man’s services and 
employ another. Maybe he has had an old and trusted miller in his 
employ for a long time, under whose administration the mill has always 
kept pace with that of his neighbors, and altogether has done good 
work and very good service. But some little thing, perhaps a personal 
matter, may cause a rupture which dissolves the business relations. We 
all know that such things do happen, and, when they do, the mill owner 
begins to cast around for another miller, and if it is a head or boss 
miller who is wanted, he considers the reputation of the various men 
within the circle of his acquaintance. He finally settles on one, and 
the negotiations are closed. Of course it is liattery to be called upon 
or to be selected from a number of applicants to take such a position, 
when the question of merit and reputation has been considered. At 
the same time it is a dangerous thing to make a change—dangerous to 
the miller and mill owner alike. As said before, the miller was selected 
because he had been doing good work. Of course he is anxious to pre¬ 
serve his good reputation, and while the mill to which he comes may 
have been doing equally as well as he was able to do, he is inclined to 
look upon it with suspicion. He looks around quietly at first, does not 
have much to say in the way of opinions, but his mind is constantly re¬ 
curring to his last position and the way he did things there, and while 
the ultimate result is all right, the means or details do not strike him 
pleasantly. In the course of time he suggests one little change or 
another, and explains it so clearly or rationally that the owner is im- 


56 


GRADUAL REDUCTION MILLING. 

pressed with the benefits which may be derived from it, and allows it to 
be done. When he asks how it is doing after this change has been brought 
about, his miller, whose mind is filled with hope, does not allow himsel 
to be disappointed, and he so explains it to others interested and with 1 
the honest belief that he has done a good thing. This makes it easier to 

4 ■** i ! ' > 

bring about other changes and alterations with the idea, not expressed 
or perhaps realized in the mind of the miller, to have the mill like the 
one he had left. If the conditions were all the same, if the machinery 
were the same, this thing might be accomplished without harm; but here 
is a mill representing another man’s ideas, which the miller now in charge 
wishes, with good intentions, to make accord with his own. But he does 
not do it at once; he does it gradually. It would be better if he in¬ 
tended to do it all, to bring about the change all at once. But this 
gradual mixture with the methods of his predecessor means nothing 
more or less than a constant series of experiments, some of which are 
almost sure to fail, and considering that everything was in good condi¬ 
tion before, and that comparisons may be made to demonstrate to the 
disadvantage of these experiments, our new man is treading on danger¬ 
ous ground. If he had a bad case to work out, if he had taken hold of 
a mill which was in a bad and unsatisfactory condition, he could afford 
to do this; he could afford to try to bring this mill to a point where the 
methods were like those in his former place. Here, where the condi¬ 
tions are so different, he has no such favorable ground to work in. The 
first time that he makes a misstep, it is backward, one which brings pos¬ 
itive discredit to him—suspicion. It is easy to see where such meas¬ 
ures in such a place may lead. 

The time is past when a miller has to sustain his position by his abil¬ 
ity to make changes in keeping with the spirit of revolution which was 
once so prevalent. It is possible for him to gain credit by regularly 
running a mill, by taking what he has and doing his best with it. If the 
flour is not satisfactory and the proprietors so express themselves, then 
is time enough to make changes with the view to better results. They 
will find this out soon enough, and then there is safety in changes; oth- 
wise there is not, to the miller. Without such reasons, he will always be 
regarded with suspicion and distrust, even if it be not expressed. His 
successes will be taken as a matter of course in fulfillment of his 
promises, implied or otherwise; his failures will be directly charged 
against him, with no credits to balance. 


GRADUAL REDUCTION MILLING. 


57 


The best machinery, the best programme and the best managed mills 
do not necessarily do the best work with the best wheat. Everything 
may be ever so complete, but if the miller fails to comprehend, or for 
any reason to take advantage of that which is set before him, he will 
fail in doing good work. It is with the most delicate arrangements and 
adjustments for making distinctions in milling matters that the greatest 
mistakes may be made. With mechanical provisions for recognizing 
and caring for all the finer differences in the milling of the stock, there 
is required a mental provision for distinguishing the uses and necessities 
for such arrangements. The failure to provide such an auxiliary is the 
failure of the machine itself. There is no object in having a complete 
mill unless an equally complete man be chosen to run it. If the finer 
distinctions be made in the reduction of the stock and its ultimate grad¬ 
ing and separations, it is only possible to have these distinctions pre¬ 
served by operating the machines in the spirit and intention of the 
original designer. It is a frequent experience of mill builders that the 
mills with which they take the most pains, those which they study the 
most carefully, and in which they make the most elaborate preparations 
for good milling, give them the most trouble. There is in mind a mill 
which was planned by a prominent and capable mill builder, which failed 
to such an extent as to reflect discredit on the firm which built it—not 
because it was inefficient in any degree, but rather because it was too 
good, too complete for the men who were to run it. They were not 
organized in a way to recognize or use its better points. One feature of 
this mill was the gradual reduction of middlings. These men could not 
see why these middlings should not be “crushed down” at once, and 
crush them down they did, and the consequence was that when they 
came to the place in the mill where they should have had their best mid¬ 
dlings, they had a lot of flat, feathery stock, which made soft, flat, gray 
flour, instead of making the best flour in the mill. The builder of this 
mill was enough of a politician to see a way out of his trouble. He 
took out that gradual reduction apparatus, as far as it applied to the 
middlings, and put in millstones, and the result was that the owners were 
happy. They were confirmed in the belief that smooth rolls would not 
do for the reduction of middlings, and that the buhrs made whiter, more 
granular and altogether better flour. 

A very large proportion of the flour made in this country is manu¬ 
factured by very simple machinery and methods. Most of these mills 


58 


GRADUAL REDUCTION MILLING. 


will one time or another be improved. There will be additions made 
with the view to the improvement of the quality of the product and hav¬ 
ing in mind, at the same time, a reduction in cost; at least this latter 
should always be a part of the scheme. More often than otherwise the 
idea of improvement in the quality is considered so seriously that the 
question of cost of production is lost sight of, and while the flour may 
be better, its cost is materially increased. The feed is richer and the 
miller eventually poorer. The real improvement in milling does not 
consist solely in bettering the quality of the flour. That is one side of 
the question, and a small one. There is no improvement in milling where 
the main question is not affected in favor ot the owner. By this is 
meant that there is no improvement where the miller does not get more 
money out of his wheat by his changes. For if he does not, why should 
he change? There is nothing in it to him in having better machinery or 
cleaner flour regardless of cost than does his neighbor. That would be 
a matter of sentiment, and not business, which latter is the side of this 
question which is being considered. In times past when there was great 
strife and great activity because of the radical changes in methods, there 
was more advantage to be gained by superiority in quality and, in a 
measure, regardless of cost; and in the enthusiasm of those times, so 
prolific of changes, this matter of sentiment and personal pride took a 
rank growth along with other things. But a little time will straighten 
this all out. The time is past when a few mills will monopolize the trade 
for a superior article of flour. The number of mills making such flour 
is daily increasing, and the names which stood up like monuments in the 
flour trade are less conspicuous because of the strife, activity and skill 
of their competitors. This change alters the character of the competi¬ 
tion. In the future it will be more a matter of cost than of quality. 
Not that quality will be any the less requisite, but because it will not be 
so serious a matter with the buyers to get the quality they desire. This 
state of affairs will call for serious consideration in the cost of manu¬ 
facture. The matter of yield and percentage of the various grades will 
force itself prominently into view. 


CHAPTER X. 


THE CAPACITY OF MILLS-THE INCREASE OF CAPACITY-THE WAY THAT IT 

IS USUALLY DONE-HOW THE COST OF THE FLOUR MAY BE INCREASED 

AT THE SAME TIME. 

The capacity of a mill is estimated by the number of barrels of flour 
it will make in twenty-four hours. One mill will grind more wheat and 
make less flour than another. One mill may make a better yield, but 
this is not the side of the case to be presented. It is a suggestion. In 
the nature of things it is not possible to make exactly the same amount 
of flour each day, nor in the nature of things is it desirable that it should 
be done. If a mill was built for the purpose of making 250 barrels of 
flour per day, we all know that it would make more than that amount 
during part of the time, and less at others. To make an exact amount 
each day would imply a uniform condition of things which could not ex¬ 
ist. If the stock were uniform the miller might not be, and if the miller 
were uniform in his attentions, from time to time he would be sure to 
notice changes in the character of the stock under his care which would 
require handling slightly dissimilar one day or one time as compared 
with another. 

We increase the capacity of a mill. For what? To make more flour; 
to make more money. If we make more money by the change it is a 
good one; but the question is as to whether this thing is usually done, 
or, on the other hand, if the same money used to increase the capacity 
could not be put to better use by decreasing the cost of production, by 
adding to the facilities for making pure flour and clean feed. The in¬ 
crease of output by overgrinding in the operation of machinery need not 
be considered. It is not a pertinent question. There is less danger 
from overgrinding when business is dull, than when it is brisk. It is 
clear to the mind of any one who thinks about it, and especially clear 
to those who have had the experience in increasing the capacity of their 
mills, that such an operation does not proportionately increase their 
profits from the year’s business, and, from what is known, it is the gen¬ 
eral opinion that this change as often leads to a loss as it does to a profit. 


6o 


GRADUAL REDUCTION MILLING. 


This increase of capacity is brought about something like this: We have, 
say, a 250-barrel mill. Business is good; we nre making money—can 
not fill our orders. If we could make more flour we could sell it readily. 
An increase in capacity suggests itself. The miller and proprietors sit 
down to talk it over. The miller has a heavy feed on the mill, about as 
much as “she” will stand, and, in truth, a little more. If they could 
take a yield in that day’s run somebody’s hair would stand up. These 
busy times are very deceitful. Margins are good. We think that we can 
make more Hour, even if it does run a little richer. We think that we 
can add a little to the feed to gain in the output of the mill. But allow 
the suggestion that these busy times do not figure out as big as we are 
led to expect. They are productive of careless milling. But to return 
to the group who were talking about increasing the capacity of the mill. 
This is a reminiscence. There are no such groups to-day. It is agreed 
that they could sell twice as much flour as they are making—have not 
quite power enough for five hundred, but think “she” would stand four 
quite comfortably. What is needed to do it? Four or five pairs of 
rolls are ordered, a purifier or two, and perhaps two or three reels, and 
in the course of time, a 400-barrel mill is in operation. It was originally 
agreed that it would take no more help, except maybe a roustabout or 
two, than for the smaller mill. But when it comes to starting up, they 
have the extra roustabouts and some inside men besides, “just to help 
get things regulated, ” but they never leave. 

Look back and see what was done and what was not done. This 
mill was increased 150 barrels above its maximum capacity by patching 
on to the reduction a little; by adding to the middlings rolls what might 
properly have belonged to them without this increase, and for the other 
smooth roll reductions the means were indefinite, and the miller and 
proprietors felt that they were lame there, but as they were making more 
flour they thought they could afford it. Any way, if necessary, they 
could make some change in the separations which would bring this out 
all right. Be it remembered that there is no arrangement of separating 
devices which can atone for marked deficiencies in reduction capacity. 
No additions were made to the scalpers, very little to the bolting sur¬ 
face. Some of the cloths were made coarser, however, to compensate 
for this; not the proper thing to do, by the way. The wheat cleaning 
machinery was entirely neglected, and the other purifiers were little bet¬ 
ter off. Here are deficiencies all around; everything cramped and 


GRADUAL REDUCTION MILLING. 61 

strained. The reductions could not be so good as before; the bolting 
much worse; the wheat cleaning machinery positively wasteful and in¬ 
sufficient. The purifying system, which was not too good before, now 
has its machines overloaded with middlings badly formed and poorly 
dusted. The mill is started. All recognize that the results are not sat¬ 
isfactory, but say that this is incident to starting new machinery, and in 
the meantime they get used to things as they are, forget to compare, 
and are partly satisfied for the time. But the buyers realize the differ¬ 
ence. They reject, protest, and perhaps claim rebates. The miller 
protests, and either pays or does not pay the claims. He says “he may 
have a little poor flour in starting; who has not?” A few days later he 
has more objections from buyers. “All nonsense; the flour is all right. 
If the market had not gone off we would never have heard a word about 
poor flour or anything of this kind.” But, in the course of time, this 
thing quiets down; no more objections. Does this mean that the flour 
has reached the original standard of excellence? By no means. It 
means that they now realize the true position of the flour, and pay cor¬ 
respondingly less money for it. The miller fondly imagines because 
they do not object that the flour is as good as ever, but he may 
notice that the old buyers who were running on his flour are taking less 
of it, if they have not abandoned it altogether. The miller has had to 
search for new customers, who buy it distinctively on its merits, regard¬ 
less of its previous good name. The flour occupies a lower place in the 
market. It is worth less money. But this is not all—it costs more. 
The yield is astonishingly high. 

The flour costs more and sells for less since the increase of capacity. 
The increase in cost is realized; the decrease in value is not. This 
means more millwrighting and more expense, and they finally settle down 
to a yield which is not quite as high as the last but higher than the old 
one. 

There is another element of loss, and that is the trade for the dull sea¬ 
son. The miller scattered his friends just at the wrong time. 

No one will consider this picture overdrawn. It is a common experi¬ 
ence rather than an uncommon one—a condition of things developed 
by prosperity. It is one of the things from which the mills are now 
suffering, and with business as it is, all think that they cannot afford 
to change the mechanical state of affairs; but it will be done, however 


62 


GRADUAL REDUCTION MILLING. 


gradually. It is these tight times which will do it. Prosperity made 
us careless, but adversity will make us careful. 

To revert to the 250-barrel mill illustration. How much better it 
would have been had the owner decided to cut down the cost of the 
flour and add to its quality by putting in this machinery. It would take 
a good deal of courage to rearrange a 400-barrel mill to make 250 
barrels of flour, but is it not more certain to make money? It does not 
take much courage to go ahead when the money is in sight. Reduce 
the cost of production and increase the value of the product. 


CHAPTER XI. 


WHEAT AND FLOUR CHEMICALLY CONSIDERED-THE PROPORTION OF ALBU¬ 
MINOIDS AFFECTING THE COMMERCIAL VALUE-THE RELATION OF CHEM¬ 

ISTRY TO THE MARKET—A GRAPHIC EXHIBITION OF THE CHEMICAL 

QUALITIES OF THE VARIOUS WHEATS-THE CHEMISTRY OF FLOUR- 

FIBRE AND ALBUMINOIDS AFFECTING THE PRICE OF FLOUR-A GRAPHIC 

EXHIBITION OF THE CHEMICAL QUALITIES OF VARIOUS MILLING PROD¬ 
UCTS. 

When anything is said to a miller about the chemistry of wheat, when 
he sees, in the course, of an article or milling chapter, chemical expres¬ 
sions and chemical discussions, he is inclined to look over that article 
very hastily, to say the least. The writer does not lay claim to an ex¬ 
tensive knowledge of the chemistry of wheat, and, for that reason, is 
not in a position to disturb any one by an extensive dissertation involv¬ 
ing the use of chemical knowledge. He feels disposed to accept the 
expressions of others who are in a position to know more about this 
subject than would be possible with him unless this branch of study were 
followed to the exclusion of all others. Furthermore, he feels disposed 
to accept the conclusions of such authorities without wading through an 
account of the means of reaching such conclusions. Prof. Clifford H. 
Richardson, assistant chemist of the department of agriculture at Wash¬ 
ington, in his bulletin No. 4, in which he presents “An Investigation of 
the Composition of American Wheat and Corn,” in explanation of the 
analysis, says: “The determination of the albuminoids in connection 
with the size and condition of the wheat, settle, so far as physical and 
chemical examination can succeed, the peculiarities of the samples in 
hand. ” From the miller’s standpoint this is all that it is necessary to 
know, and, as the size of the berry is not a very important matter to 
him, the relative percentage of the albuminoids is the principal thing 
after all. There is a distinct relation between the percentage of albu¬ 
minoids and the commercial value of wheat, or, to express it differently, 
there is a distinct commercial relation between the proportion of albu¬ 
minoids in various wheats and the flour made from those wheats. We 
may take a table which shows the albuminoids, as does the one which 


64 


GRADUAL REDUCTION MILLING. 


follows, and select the wheat which makes the highest priced Hour. This 
is a convincing fact; it is the method of estimating the worth and value 
of wheat and flour—that is, in a relative way. The flour from the wheat 
which has the largest proportion of albuminoids is worth more money, 
and sells for more than does flour from a wheat which has a smaller pro¬ 
portion of albuminoids. We may take as illustrating and verifying this 
statement, the hard Dakota wheat, with its 15.54 per cent, of albumin¬ 
oids. We find on comparing it with Ohio Fultz, which has 12.95 per 
cent, of albuminoids, that there is the relative difference in the flour made 
from those wheats. There is nearly always fifty to seventy-five cents 
difference in the selling price of those flours in favor of the one which 
has the largest per cent, of the albuminoids. There is the Mediterran¬ 
ean wheat, with its 16.1 per cent. The price of the flour from such 
wheat does not quite reach that of the flour produced from the wheat of 
the far Northwest. It would be possible to take two milling samples of 
wheat and so mill them that the one which contained the larger proportion 
of the albuminoids would sell for the less sum of money. This would 
be for mechanical reasons, however—for the reason that one wheat was 
not milled as well as the other. But where the milling is approximately 
uniform there will be just the difference in the price of the flour which is 
indicated above, unless the wheat be of such a character as to make it 
impossible to mill it properly. In former years, previous to the introduc¬ 
tion of the new process, hard spring wheat would have come under this 
head. 

New process milling, intelligently carried out, removed the former 
difficulties in the way of handling spring wheat. New process milling 
took the wheat, made it into middlings, cleaned and purified it, and made 
it into flour. It took the wheat which was rich in albuminoids, and by 
so handling it as to remove the deleterious portions, it put the flour 
at the head of the list. It is just as impossible to make an 
article of flour out of a wheat which is deficient in albuminoids that 
will compete with one which is not so deficient, as it is for a corn mill 
to compete with a wheat mill in supplying the same goods. It is not 
possible for a mill which handles Fultz wheat ever so skillfully to com¬ 
pete with a mill which handles long berried Mediterranean wheat even 
tolerably well. The writer has known millers around through Ohio and 
Illinois to periodically tear to pieces and reorganize in order to compete 
with some small mill which was able to sell its flour at much higher 


65 


GRADUAL REDUCTION MILLING. 


prices in the eastern markets than they. It took a long time to find out 
the reason. It was discovered that one mill was running on Fultz wheat 
and the other on long berried Mediterranean. Fultz has 12.95 per cent, 
of albuminoids and the Mediterranean 16.1 per cent, of albuminoids, 
and it is altogether impossible to supply the deficiency in milling. The 
mill which handles the better grade of wheat will get more money for its 
Hour than is possible from Fultz wheat. The same is true of the vari¬ 
ous varieties of Northwestern wheat, and may be illustrated in a very 
practical way by recurring to the records of the mills which use the bet¬ 
ter varieties. It may be well to say that the albuminoids in the wheat 
imply its nutritive value, and at the same time indicate the proportion 
of gluten. In considering wheat in a milling sense it might be in order 
to say something about the physical qualities of its structure, but being 
a subject th it is well understood, and one that is so prominently brought 
to the mind of the miller from time to time, and as all wheat is approx¬ 
imately the same in structure, time and space will not be taken to con¬ 
sider this matter. The following table illustrates, in a graphic way, the 
relative sizes of wheat and proportions of albuminoids in the various 


wheats named: 

Grammes. 


Virginia. 

Osterey.3 5^5 

Red. 3465 

West Vi ginia. 

Early Amber. 

Osterey.3-39 2 

Alabama. 

Dallas. 447 

Ohio. 

Clawson. 3-3 

Michigan Amber.4-8 

Zimmerman. .3-3 2 8 

Silver Chaff.3- 2 7 

Lancaster.3-887 

Golden Straw.3-759 

Rice.3-393 

Mediterranean.3.94 

F ultz. 3-5°5 

Egyptian.-.3-565 

M INNESOTA. 

No. 1 Hard.2.926 

No. 1 Hard. 3-57 

Selected Samples No. 1 Hard.3-354 

Dakota. 

Average of the wheat crop of ’83-3.15 1 

Colorado. 

Average of the crop of 1882.4 283 

Average of the crop of 1883. 3 - 94 i 


a: 


(5) 


Albuminoids. 

12.60 —— 
11.2 — 

10.85 

11 3 — 


11.20 


* 3-83 

11 - 73 

1313 

1 *-73 
15-05 

13.48 
14.18 
16.10 
J 3 -i 3 

12 - 95 






13-83 

25- 2 3 

14.40 


14-54 

13.04 

12.74 


























































66 


GRADUAL REDUCTION MILLING. 


The falling off in the average of albuminoids in Colorado wheat is 
shown as follows: 


Crop of 1881. 13 - 4 2 

Crop of 1883... 


Below we give a table which indicates the quality of a number of rep¬ 
resentative wheats of the spring and winter wheat country: 

Weight of 100 Grains. Albuminoids. 

Minnesota, No. 1 Hard.3.57 I 5- 2 3 1 

Dakota, average crop of 1883. 3 . 15 1 . .. ■■ J 5.54 

La Moure county, Dakota .3074 ' 18.03 

Ohio, Mediterranean.3.94 16 10 

Ohio, Fultz.3.505 — 12.95 -m—— 

The next table shows the difference between two wheats, spring and 
winter, grown on Dakota soil: 

Weight of 100 Grains. Albuminoids. 


Winter wheat. 3 - 5 T 3 " 10.68 • 

Spring wheat.2.755 " " I 4-35 1 


What was said under the head of wheat as regards the proportion of 
albuminoids might be said, in a limited way, of dour. Wheat which 
will produce flour that contains the largest proportion of albuminoids, 
as we understand it, is the most valuable wheat, and flour which con¬ 
tains the largest proportion of albuminoids and the smallest proportion 
of fibre and other impurities is the best flour. It cannot be said, in the 
broad way in regard to flour, that that which contains the largest pro¬ 
portion of albuminoids is the most valuable flour, in that the impurities 
which there may be in flour have a tendency to destroy the value given 
to it by the large proportion of albuminoids. Thus, in estimating the 
value of flour, we have to consider it on the basis given above; that is, 
with reference to the small proportion of fibre, as well as with reference 
to the proportion of albuminoids. Below is given a table which illus¬ 
trates, in a graphic way, the proportion of albuminoids and fibre in the 
various stocks named. We shall notice that the value is given to the 
flour by its freedom from fibre. The bakers’ flour from Pillsbury & Co.’s 
mill contains .33 per cent, of fibre and 14.88 per cent, of albuminoids; 
the patent 12.95 per cent, of albuminoids and .18 per cent, of fibre; the 
low grade contains 17.95 per cent, of albuminoids and .93 per cent, of 
fibre, which latter element, in that the proportion is large, keeps the 
flour very low, notwithstanding the fact that the proportion of albumin¬ 
oids is high. Another thing which may be noticed, as exhibited by 
these tables, is that the closer to the bran the reductions approach, or 
rather as the reductions advance toward the finishing process in the 

























GRADUAL REDUCTION MILLING. 


6 7 


cleaning of the bran from the first to the sixth break, the proportion of 
albuminoids increases. The proportion of albuminoids is larger on the 
last break than on the first. 

Table showing the proportion of albuminoids in the various products 
of C. A. Pillsbury & Co.’s milling: 


Albuminoids, 
Per cent. 

Wheat as it enters the 

mill.14.18 ' 

Cockle and screenings. 13.65 
Scourings removed by 

cleaners.11.55 “ 

First break chop. 12 -95 “ 

Second break chop._12.60 ■> 

Third break chop.12.70 ■ 

Fourth break chop-14.18 ■ 

Fifth break chop.*5-75 1 

Sixth break chop.17.28 «• 

Middlings Uncuaned. 

No. 1.13.48 ■ 

No. 2........13.30 

No. 3.13.13 

No. 4.13 83 

No. 5.14 53 

Middlings Cleaned. 

No. 1.13-13 


Albuminoids, 
Per cent. 

No. 2.12.78 — 

No. 3.13.13 — ■ 

No. 4.13.30 1 —■ 

No. 5.14 35 ' 

Tailings from Purifier. 

No. 1.16.10 

Nos. 2, 3, 4 and 5... 14 35 

No. 6.14.53 

Re-purified mids-14.88 

Finished Flour. 

Bakers’.14.88 

Patent.12.95 

Low grade. 17.95 

Break flour.15 40 

Flour from tailings, 
average.13.40 

Germ, average.30.08 

Bran dust flour.13 65 

Dust from dust catch¬ 
er.14.14 


Table showing proportion of albuminoids in the various products of 
Herr & Cissel’s milling: 


Albuminoids, 
Per cent 

Mixed winter wheat, 


cleaned.12 78 

First break.13,48 

Second break.13.13 

Third break. i3- T 3 

F'ourth break.13-65 

Fifth break.15.40 

Sixth break.12.10 


Albuminoids, 
Per cent. 


First middlings.10.68 

Second middlings.10.50 

Third middlings.11.65 

Patent flour. 9.98 

Clear flour.11.03 

Low grade.14.18 

Feed middlings.16.45 

Bran middlings.16 45 


The products furnished from C. A. Pillsbury & Co.’s mill are so com¬ 
plete as indicating the various divisions and classifications of products- 
as to provide means of obtaining exact and complete chemical knowl¬ 
edge of the chemical effect of the processes of manufacture on the 
various products. The albuminoids from the tables of Mr. Richardson: 
have been selected as indicating the nutritive qualities of the various 
products, and the graphic tables which are given bring into view some 
very noticeable facts. 

It may be noticed that the cleaning of the middlings makes very little 
difference in the proportion of albuminoids. The albuminoids of the 





































































68 


GRADUAL REDUCTION MILLING. 


tailings show very large, owing to the germ. The low grade Hour is the 
richest in albuminoids, bakers’ next, and the patent is the lowest. The 
showing made by the germ is quite pronounced. It is the large propor¬ 
tion of oil and fiber which the low grade Hour contains that destroys its 
bread-making properties. 

Mr. Richardson’s table makes the following showing of the proportion 
of fiber in the different grades of C. A. Pillsbury & Co.’s flour: 

Fibre, 

Per cent. 


Bakeis’.33 

Patent.18 

Low grade.93 


We may see that the value of the flour is affected, first by its purity 
and second by the proportion of albuminoids. We may know that if 
the albuminoids be not present to the desired extent, the Hour will 
not take a high rating in the market. It is the experience that the rela¬ 
tive value placed upon flours in the markets by the ordinary trade con¬ 
ditions and the relative value indicated by the chemical constituents are 
the same; and it may not be out of place to say that in time Hour in¬ 
spection may include a chemical analysis which will fix its proper stand¬ 
ard. It would be said that flour contains a certain proportion of nutri¬ 
tive and glutinous qualities and a certain other proportion of deleterious 
qualities, and for that reason belongs to a certain grade and is worth so 
much money. This would be systematizing and fixing upon an exact 
and intelligent basis the inspection of flour. Such a method would 
place the inspection of flour outside of mere human judgment and 
within the scope of absolute formulated and scientific information. It 
would place the grading of flour outside the range of guess work and 
within the range of absolute certainty. 









CHAPTER XII. 


FLOUR FROM A MILLING STANDPOINT-DEALERS IN FLOUR THE BEST 

JUDGES-THE COLOR AND STRENGTH OF FLOUR—THE DOUGHING OF 

FLOUR-GRANULAR FLOUR—PATENT FLOUR-LOW GRADE FLOUR—HOW 

TO GRADE FLOUR-THE PLACE TO STOP MAKING FLOUR—THE BEST 

MILLER. 


The dealers in flour are better judges as to its quality than the makers. 
This is a general statement, and of course there are exceptions to it. 
But take the sellers and buyers of flour in the large markets and con¬ 
trast them with the millers of the large manufacturing centers and the 
comparison will be to the disadvantage of the latter. The facilities for 
knowing flours are better in the flour markets than in the mills. Judg¬ 
ment or knowledge is gained by experience or comparison; differences 
cannot be recognized without comparisons. The facilities for such ex¬ 
aminations are the best where there is the greatest variety of flours. 
There is no better place to learn about flour, to be forced to recognize 
the smallest and most minute differences, than on the New York 
Produce Exchange. It is here that one sees nearly every flour manu¬ 
factured in the United States. It is here that the best flours are most 
readily appreciated and where the demands of the trafie are the most 
fastidious. On this exchange there is less dependence put upon brands 
and trade marks, and more upon the judgment of buyers and sellers, 
than any other market in this country, to say the least. There is no 
place better calculated to arouse a miller to the necessity of good judg¬ 
ment in the examination of the products of his mill. There is no place 
which will more thoroughly take the conceit out of a miller than this same 
place. If a miller will give himself half a chance, he can determine his 
exact position with reference to other millers; he can convince himself 
with very little trouble. 

There are two main points to be looked at in the manufacture of 
flour. Color first and strength next. It might be said that the order of 
their importance is not correctly given, but when one calls to mind the 
fact that the darkest flours are often the strongest, it is not difficult to 


/ 


7o 


GRADUAL REDUCTION MILLING. 


see this point. What is wanted is white and strong Hour. If it is very 
white and of very little strength it will not bring a high price, or if it is very 
strong, and of poor color, it in ly be not so good. One of the best color 
tests was first brought prominently to notice by Emmerich Pekar, the 
author of “The Wheat and Flour of Our Earth.” His method was 
to place side by side two or more flours on a card or board, or a piece 
of glass, and after pressing them down with a spatula, to dip them in 
water. Such a process emphasizes the difference in color, and makes 
it much more conspicuous than in the dry dust. But this merely gives 
the comparative colors of the different Hours. 

The doughing test gives both color and strength. Of course it is not 
so quickly done. One great fault noticed in doughs made by millers is 
that they make them too dry; they get too much Hour in proportion to 
the amount of water used. This kind of doughing does not show the 
absolute strength or sponginess of the flour. It works dull and heavy, 
and cannot show its better qualities if it has them. A dough which is 
too dry does not spring back, or show spongy or elastic qualities. The 
proper consistency cannot be expressed in words, but with these points 
practice will determine what is correct. A dough which is neither too 
soft nor too dry should be allowed to set a short time, to allow the 
granules of flour to dissolve, alter which it will show what there is in 
the flour. One great mistake made by people who are not experts is 
that they do not get the proper mixture the first time; that is, they get 
it too wet and then dip it in the flour, or add more from time to time 
until the desired consistency is obtained. Such doughing cannot make 
a correct exhibit of the qualities of the flour. It will show it worse than 
it is every time. For example, it will be darker in the wet and dry 
dough than it would be if the flour were all mixed at once, and further¬ 
more it will not show its full' strength. Another thing that this kind of 
doughing does is to make the flour sweat and get sticky in working. 
Under other circumstances this would indicate that the flour was dirty, 
that is, improperly purified and bolted. It is a very easy matter to make 
an appearance of a difference of from twenty-five to fifty cents a barrel 
in two flours of equal value, or in two doughs of the same flour. This 
may be done carelessly, ignorantly or purposely. If done purposely 
the above method will accomplish a good deal, or if two doughs be 
properly made, quite a difference can be made in handling. For in¬ 
stance, say a flour buyer is doughing your flour against another and de- 




GRADUAL REDUCTION MILLING. 


71 


sires to make it appear that his is the best; he may dough them all right 
as to consistency, but may make yours appear weaker by working it down; 
or a not uncommon habit is to allow the dough to get warm by holding it 
in the body of the hand while working his own with the ends of his fingers. 
This leaves his Hour cool and strong, and yours warm, soft and sticky. 
Another less flagrant deception is to work the flour which it is desired 
to misrepresent nearer the body of the hand—not on the ends of the 
fingers—but rather up as much on the third joint as possible. This 
makes a dough warmer and works it down quicker than by working it 
as near the tips of the fingers as possible, which will keep it cooler. In 
fact, by working a dough this way, it can be worked a good while with¬ 
out letting down or getting soft and sticky. Another thing which gives 
one flour prominence in strength over another is by spreading it out 
thin and exposing it to the air or a draft, which makes it cool and tough. 

Flour will work stronger in a cool atmosphere than in a warm one. 
Cold water will make a dough start out stronger at the first working than 
will warm water. All these little tricks of doughing cannot do any 
permanent good, or a victim to them any permanent harm, but it does 
no harm to know there are such. As far as the experience of the 
writer goes, he cannot see that any information can be gained in regard 
to them by drying out the doughs, by putting them in the stove or other¬ 
wise. The fact of one flour drying out whiter than another of the same 
general grade in this way does not indicate anything in reference to their 
baking qualities. For instance, take Fultz wheat clear, and Mediter¬ 
ranean wheat clear; the latter will almost invariably dry out darker than 
the former. But at the same time it will bake a great deal whiter, and 
the proportional difference in the color of the two flours baked will be 
the same as between the wet doughs. The Mediterranean flour will 
show whiter in the wet dough than the Fultz wheat, and proportionally 
whiter in the bread, but as said before, the Fultz wheat flour will dry out 
the whiter in the ordinary method of making doughing tests. It is for 
this reason that the dry dough does not signify anything in testing two 
flours. If one knows just what kind of wheat they are made of it may 
enable him to tell something about the milling—otherwise not. 

Sharp, granular, or large-grained flours are not as white in color as 
small-grained, soft flours. They show their impurities to a much greater 
extent. The difference is in appearance only. The specks and impuri- 
ies are of such a size as to be readily seen in the larger grained flours, 


72 


GRADUAL REDUCTION MILLING. 

and for this reason a soft-grained dour may contain a much larger pro¬ 
portion of impurities and yet show cleaner than the larger grained dour 
with which it is compared. But this is not the reason for the difference 
in color. The granules of a large-grained dour cast shadows one upon 
the other in such a way as to make the whole appear darker than where 
the granules are smaller and the shadow less. To explain this, a gravel 
bed looks lighter than a pile of boulders of ihe same geological forma¬ 
tion. Or, again, the dour from middlings shows whiter than the mid¬ 
dlings themselves, notwithstanding the fact that it may not have been 
bolted. Say one was taken before going through the roll and the other 
after. It is a mere difference of size and not of composition. The 
largest particles cast the heaviest shadows, and consequently show the 
darkest. 

Jn the sale of dours in certain sections of the country this thing has 
to be met, more particularly where they rely on the spatula and the 
thumb nail. The writer has seen a miller set a middlings buhr by his 
nose. Say he had dirty middlings, as such millers generally have; he 
would set the buhrs so close that he could smell them, and then raise them 
the merest shade. This miller made white dour, but the dour did not 
make white bread or a large loaf. 

Patent dour is not any particular part of the wheat berry. It is 
not as strong as the bakers’ or clear dour, and not as strong as the 
low grade. We frequently hear it said that the patent dour is only made 
up of the harder or more glutinous portions of the wheat. The low 
grade, or the dour from next the bran, would come as near meeting this 
definition as does the dour from the middlings in the present system of 
manufacture. In the old system of milling with the millstone, and 
especially the low grinding system, the middlings were that portion of 
the wheat which was best calculated to resist the action of the millstone; 
that is, it was the hardest and most glutinous portion. The present sys¬ 
tem of making middlings with corrugated rolls does not depend upon 
the varying hardness of the different portions of the wheat to make mid¬ 
dlings. Of course where the wheat is harder it will be more brittle; but 
by this system the making of the middlings is not merely an incident in 
the manufacture of dour. It is the principal purpose in the reduction 
of wheat by corrugated rolls; and by this method the wheat is broketi 
into middlings, not ground into dour with a portion incidentally remain¬ 
ing as middlings, because of its hardness. For this reason patent dour, 



GRADUAL REDUCTION MI LUNG. 


73 


or the flour made from middlings, according to the present methods, 
does not necessarily mean that it is the flour from any particular part of 
the wheat berry, as is frequently understood. As we now understand it, 
the purpose in milling is to make the largest proportion of middlings, 
with the intention of making a proportional product of pure flour. And 
whereas the middlings were previously an incident of reduction and not 
the desired portion, it is now the reverse, the middlings being in larger 
proportion and the flour or dust of their preparation being the incident. 
Patent flour means pure flour, and a single granule of clear or low grade 
flour may be as good as a single granule of patent flour, but its value is 
depreciated by its association with less valuable material. 

There is something which may be said on the low grade question, 
and that is, bluntly, that there should be two low grades instead of one. 
There is just one place to stop making flour, and that is where the 
lowest grade of flour and the best portion of the feed approximate the 
same price. There is no more reason for running all the low grade into 
one packer than there is for so doing with the higher grades. The logic 
which advises the throwing away of any quantity of superfine flour in 
order to bolster up or to keep the low grade “rich enough,” cannot be 
accepted. If the desired grade is XXX, anything which will lower that 
grade may be put in another barrel, and not sold at the same price as 
feed. A small proportion of low grade flour will lower a much larger 
quantity of high grade. A quantity of superfine flour may and often 
does contain fifty and sixty per cent, several grades higher, a large por¬ 
tion slightly above it, and a small quantity of fine or other lower grade, 
which serves to lower the whole. The above system of grading is ac¬ 
cording to St. Louis methods, and, by the way, is the best system in 
this country for low grades. It has been adopted by the Indianapolis 
board, and should be recognized by the principal markets as standard 
on winter wheat low grade. This method of separating the low grades 
does not necessarily require a packer for each. They may be run into 
sacks, graded and packed when convenient. This is one element of 
Hungarian milling. It often happens that two or three per cent, of the 
lower end of the red-dog may be spouted out in this way, the principal 
product being materially improved and the smaller portion of a quality 
above the price of feed. The practice of running everything below a 
choice clear or bakers’ into one grade, is an absurdity. As to the yield 
proper, it is a matter of detail. The question as to how low it can be 


74 


GRADUAL REDUCTION MILLING. 

made can be decided by putting in enough machinery to make the last 
Hour and the feed meet in price, or as nearly so as will represent the 
difference in cost of manufacturing Hour or feed. 

As a matter of practice, we cannot make these separations as exact 
as is here implied. It is easy to understand, if you stop to think about 
it, that the range from a good clear Hour, such as a fancy or a choice, to 
the super, is too wide to be natural or right. In most mills there can be 
found Hour running into the low grade mixture which is well above 
superfine in grade, and this being the case, there must be other products 
which are well below the superfine. Now, if we could make arrange¬ 
ments to separate these extremes, rather than to run them together, we 
would have a certain proportion of Hour which is quite good, or inter¬ 
mediate, in quality, and a certain other proportion which is below the 
super standard, and we could then judge exactly whether it would pay 
to run them together or not. The general experience is that it does 
not. Sometimes we know of millers running patent, clear and low grade 
all together, for the purpose, as they say, of making a “cheap mixture.” 
It generally makes it so cheap that there is no money in it. 

There are those who begin throwing stock into the feed pile where 
others begin to make low grade Hour. This is where the lowest grade 
of Hour is XXX, which necessarily implies that there must be still other 
and lower grade flour going into the feed pile. What better thing could 
there be to do than to take this latter Hour and put it into a packer by 
itself? People who say that a barrel of winter wheat Hour cannot be 
made out of less than four bushels and forty-eight pounds of wheat, or 
more, are making a low grade which will pass XX and XXX in St. 
Louis. They are sending the rest of the Hour which would go to make 
up a lower yield into the feed. Millers who are making these fancy low 
grades frequently pride themselves on it, but as a fact it is not a matter 
for pride, because it is a source of loss. 

The miller who adds the largest proportion of value to a bushel of 
poor wheat is getting a better yield than he who adds a smaller propor¬ 
tion of value to a bushel of good wheat. To consider the question of 
yield as broadly as is here implied, we have to take into account the 
patent Hour, the clear Hour, the low grade Hour, and the feed, making 
the best grade of patent Hour and the cleanest feed go together in the 
matter of yield. 'Then we should add its quality, and the quantity 
and quality of the clear and low grade, and finally, the value of the feed. 


75 


GRADUAL REDUCTION MILLING. 

I hus we see there is more in this than a casual glance would indicate. 
Now, what is the best yield in milling? It is such as will make the best 
yield of patent flour and the most of it—that which will make the best 
clear and the most of it, and finally, that which will make the best low 
grade and the most of it. 

We hear millers talk about the small quantity of low grade which they 
make. Now that is all right, if it means that they so handle their stock 
that there is only a small portion of low grade stock in the mill—only a 
little material left out of which to make low grade flour. What we want 
to do in order to get a good yield and get the most money out of the 
wheat is to use our best endeavors to get all the high grade hour we can 
out of it, and when we realize that we have done the best thing possible 
in this process, we must be equally zealous and active in getting all the 
low grade Hour we can out of what remains. The separations should 
be as exact as possible; we do not want feed in the hour, nor hour in 
the feed. Again, we do not want low grade hour in the high grade 
packers, nor high grade hour in the low grade packers. All this influ¬ 
ences the yield—of money. 

We frequently hear people say that it does not pay to make a good grade 
of hour in their market. Such people generally say that what they want 
to do is to make a “good, common, straight grade,” whatever that means. 
English travelers in this country used to talk that way. A few months 
ago a milling paper contained an article advising the millers to 
make more low grade, saying that they would make more money in that 
way. High grades, it said, were too numerous. To go a little farther 
with these illustrations: The writer met a miller a few weeks since 
who was mixing what he called the sixth reduction middlings, which 
were of a quality suited to red-dog, with his high grade middlings. 
When asked if he thought that paid him, he said yes; that he did not 
think it paid him to make too high a grade of Hour. It was suggested 
that he mix a little sawdust, and if the community in which he lives is of 
the kind he described, probably he will prosper. Furthermore, a re¬ 
cent article advises millers not to make any high grade flour. Now, 
if these things were not so common, it would be a waste of time 
to write about them. But this idea is more prevalent than would be 
generally supposed. Now, every mill cannot make this highest grade 
of flour; but the thing for each mill to do is to make the best flour which 
can be made in that mill, and as much of the high grades as possible 


76 GRADUAL REDUCTION MILLING. 

Under such circumstances it costs no more to make the tiour of the best 
grade possible in each mill than it does to make it poor, mean or ordi¬ 
nary. The cost being equal, it is better to sell a good Hour for a medium 
price than it is to sell a medium hour for a medium price. The forme 
is sure to pay the best in the end. 




CHAPTER XIII. 


THE RELATION OF THE YIELD TO THE QUALITY OF 'I HE FLOUR-THE 

PROPER PRODUCTION OF LOW GRADE-THE LIMIT OF FLOUR PRODUC¬ 
TION-THE PROPORTION OF MILLING MACHINERY-UNIFORM LOW 

GRADES NOT POSSIBLE WHEN HIGH GRADES ARE UNIFORM-THE PROPER 

PLACE TO DETERMINE THE AMOUNT OF FEED ON THE MILL. 

If a miller makes a very excellent quality of Hour, it is often imputed 
to him that he takes a large amount of wheat out of which to make a 
barrel of hour. There is no reason for such a conclusion from such a 
basis. As every one knows, the quality of the hour is dependent upon 
the quality of the separations, and where one miller makes a better 
hour than another, he does it by making better separations; and in the 
ultimate result he gets the high grade stock into the high grade packer, 
and the low grade stock into the low grade packer. It does not follow 
that because he makes a high grade patent or clear, he throws the 
low grade hour into the feed pile. Or, to go into this thing a little 
farther, the making of superior high grades does not imply that question¬ 
able stocks are all run into the low grade or red-dog. The same good 
judgment which makes a superior high grade hour will also discriminate 
and use the same methods with reference to the intermediate and lower 
grades. In order to maintain this high standard mentioned, it is merely 
necessary that exact separations should be made. It does not mean 
that a large amount of high grade stock should be thrown into the low 
grade or into the feed pile in order to get a little high grade hour. Good 
hour is like good anything else; it is simply the absence of bad. 

The best mi ling is that which gets the most money out of the wheat. 
This means to make all the high grades possible, and when through 
making high grades, lo make all the low grades possible. One division 
may be independent of another. The fact that one miller makes more 
high grade than another, does not always signify that he has the best 
means. The fact of one miller making more low grade than another 
cannot necessarily mean that he is less skillful than another. It may 
mean that he has more of a mill to make it on, and consequently makes 


78 


GRADUAL REDUCTION MILLING. 


more of it. He gets more low grade stock into low grade Hour than his 
neighbor and less into the feed. According to this, the best milling, in 
the sense of the definition given, does not always locate the most skill¬ 
ful miller. Looking at it in a personal sense, the most skillful miller is 
he who does the best with what he has. He may do this and still not 
gain the position which he would have if better means were at his hand 
and he were doing the best milling in a milling sense. 

There are a great many mills in the country which are doing good 
work as to quality and poor work as to quantity. The Hour is good and 
the yield high. There is another class where the yield is reasonably 
low, and the flour not so good. The reason for this is to be found in 
the incompleteness of the mills. There is not enough to them. There 
is nearly always enough mill to make good flour by throwing good stock 
into the feed bins. There are very few mills which can make good high 
grades, a fair proportion of low grades, and still finish well. In the 
effort to do this when there is not enough mill, things are mixed, high, 
low and intermediate together, and the result is correspondingly unsat¬ 
isfactory. The remedy for this is more mill or less work. 

In putting in extra reduction machinery for the purpose of getting a 
better yield, it is not always necessary or advisable to disturb the 
arrangement of the other parts of the mill. All that remains to be done, 
and which, considering the object in view, cannot but be satisfactory, is 
to take the better portion of the material going into the feed pile and 
reduce and bolt it by itself. In this way the question of yield can be 
settled, and the point which can be reached is limited only by the desire 
of the miller. He can go on reducing and bolting in this way until the 
feed and the flour are the same color. This, of course is not desirable; 
it is an extreme illustration; but it is desirable to keep on making flour 
until the feed and the lowest grades of flour approximate the same price. 
It might be said that these last lower grades would injure the low grade 
proper. That is no doubt true, and it is for this reason that more than 
one low grade should be made. There are those who will say that this 
is too much trouble, but by the method named one can make the ordi¬ 
nary low grade flour to be sold at the usual price of such flours; and, in 
addition to this, flour can be made which is higher in price than the feed. 
Such a difference will represent a difference in profit when due allow¬ 
ance is made for the difference in the cost of manufacture. Anything 
which makes money cannot be said to be troublesome. 


79 


GRADUAL REDUCTION MILLING. 

Assuming that the various parts of the mill are properly proportioned 
for the reduction of the given quantity of grain in a specified length of 
time, it is fair to presume that there must be certain guides as to whether 
the mill is overworked or underworked. In speaking of the proper pro¬ 
portion of the parts of the mill, are meant such arrangements or pro¬ 
visions that one part of the mill will take care of, in the desired manner, 
the material prepared for it elsewhere, and at the same time will properly 
handle such material with reference to future manipulations. For in¬ 
stance, there should be purifying capacity for the middlings to be handled, 
or reduction capacity for the same, and so on throughout the entire mill, 
so that no one part will have more than it ought to do, while another has 
less. As has been said, under such a condition of things, it is fair to 
presume that there would be some proper guide which would indicate 
whether a mill was underworked or overworked. For instance, if the 
feed is rich and the other parts of the mill appear to be doing their work 
within the range of possibilities under existing circumstances, it will be 
clear that there is too much feed on the mill. On the other hand, the 
fact of the feed being clean would not indicate that the feed on the mill 
was too light, clean feed being desirable. But it may be possible to have 
clean feed and at the same time to have pulverized feed going into the 
flour, which means that the stock was cleaned, and the flour taken out, be¬ 
fore the low grade material reached its proper stage in the mill, implying 
that the leed on the mill was too light, which would mean that there was 
pulverized bran and other feed going into the low grade flour packer, 
and low grade flour going into the higher grade packers. The fact of 
stock going through a 12 or 14 cloth does not mean that it is flour. If 
it did, a barrel of flour might be made out of 196 pounds of cleaned 
wheat, with the addition of 6, 8, or 10 pounds for invisible or unaccount¬ 
able loss. The mill being properly proportioned, as stated before, and 
in the light of what was just stated with reference to the feed and low 
grade Hour, it is fair to say that the judgment of the miller as to whether 
he has the proper feed on the mill is worth the most, is more certain to 
be right, when formed by an examination of the stocks at the tail ends 
of the mill, by which is meant the feed, the low grade flour, and the last 
of the bakers’ or clear Hour reels. It is a safe way to run a mill with 
reference to the cost and quality of the products. It means a umfoim 
yield and a uniform flour, as to the high grades. 

It is not possible to have uniformly clear feed, unifoim high grades of 


8o 


GRADUAL REDUCTION MILLING. 

Hour, and at the same time keep the low grades at a fixed standard. 
There must be some place to account for the difference in the quality of 
the wheat ground. If one makes uniformly clean feed, he cannot make 
uniform Hour; or, if the Hour is uniform, the yield, as influenced by the 
feed pile, cannot be the same from day to day. As it is desirable to 
make clean feed all the time, and high grade Hour up to a fixed stand¬ 
ard, it follows that the irregularities must come in the low grades, which 
latter should be inspected as they are packed, and the different grades 
marked. Experience shows that there is a constant variation in the 
quality of the low grades where the other Hour is exact as to quality one 
time with another, and the feed uniformly clean. This difference is not 
great, but it is a marketable one. It is a very simple matter to inspect 
low grades as they are packed. When the mill is not too large, it can 
be done by the head miller, or some other person whose time is not en¬ 
tirely taken by routine work, such Hour being packed out at a regular 
time each day. 

In a stone mill, a good place to determine the proper feed is at the 
cut-off from the last chop reel. If it is too thin and sharp, put on f ed; 
if too soft, take it off. In this way the chop Hour is sure to be uniform, 
and the fine middlings which tail over this red cannot contain an un¬ 
usual quantity of dust or Hour. In some mills it is possible to run these 
reels with uniform results without changing slides except on rare occa¬ 
sions, by changing the feed on the buhrs, as stated above. In this way 
the flour is not liable to be hurt by radical changes from hard to soft 
wheat. As an illustration of this point, the experience of one year is 
recalled, when the harvest months were hot and rainless, and the new 
wheat came in very hard and brittle, much more so than the old wheat 
which was being ground. It so happened that the supply of old wheat 
was exhausted late one afternoon, and, as business was pretty brisk, it 
was necessary to begin grinding the new wheat at once. It was so hard 
that it flew all to pieces, bran and all, as soon as the millstones touched 
it. This was calculated to make the cut-off from the last chop reel 
run sharp, but the miller on watch, who had been drilled into the idea 
of determining the feed of the mill by this spout, gave the buhrs work 
enough to do to bring it around to the proper point. Of course the 
grinding was not as good as it was with the proper feed, but it kept the 
flour up, and the packer register the next day showed that the mill had 
made 25 per cent, more flour than ever before. If the miller had been 





GRADUAL REDUCTION MILLING. 81 

running by the slides under the conveyors, it is hardly probable that he 
would have reduced the capacity of his chop chest one-half, and even if 
he had, it would have been done so gradually, and taken so long, that in 
the meanwhile poor flour would have been made. In looking back after 
the thing is all over, one might say that the miller could have made the 
proper changes at the right time, but when one thinks that the mill 
might have been run for months with the variation of from four to eight 
slides, it is not at all unnatural to conclude that there are very few mill¬ 
ers who would have had the stamina to cut out from twenty-five to 
thirty feet of flour cloth at one time. Such a plan is suitable only to 
stone mills of small or moderate capacity. Large buhr mills or roller 
mills would involve work disproportionate with the result. But for 
small mills, the first plan suggested is feasible. Other things being 
equal, it is not an unnatural thing to grind as much stock as can be 
finished properly, and the proper amount is mostjclearly indicated at the 
tail end of the mill, if the mill is properly proportioned. 


(6) 


CHAPTER XIV. 


OFFAL-SCREENINGS, FINE FEED, AND BRAN—THE PROPER PLACE TO STOP 

MAKING FEED—BRAN COMPRESSING MACHINE AND ITS EFFECT ON THE 

MILLING TRADE-WEIGHT OF THE FEED NO GUIDE TO THE YIELD- 

BROAD, CLEAN BRAN INDICATIVE OF GOOD GRINDING. 

Offal is that part of the milling product which is not sold as flour. It 
includes the foreign impurities from the wheat, the bran and the 
tailings from the low grade dour reels. This latter product has different 
names in different parts of the country. It is called shorts, middlings, 
feed middlings and fine feed. Fine feed is the most common name. 
The proportion of offal from the wheat, the foreign impurities there¬ 
from, varies with different qualities and kinds of wheat. The average 
may change with different crops. One year there will be more screen¬ 
ings and light grains than another. It would hardly be worth while to 
give tables or statements which would represent the average amount of 
such offal at any one time, as the quality of stock varies in different 
parts of the country. For this reason statements or exhibits of this 
kind w r ould be misleading, or, to say the least, valueless. Another 
reason for not giving these statistics is that, as regards the contained 
foreign impurities, the proportion of stock taken by diderent millers 
from wheat of the same quality may vary, and it may be that he who 
would take out the larger proportion of stock with his wheat cleaning 
machinery, would do this without adequately cleaning his wheat. It 
does not follow that he who takes the largest amount of stock from 
the wheat in cleaning it, cleans it the most perfectly. One man may 
take out less than another and still send the wheat to the reduction ma¬ 
chines in better order, in better shape for reduction. One miller may 
crowd his cleaning machinery, or it may be imperfect in arrangement, 
or the system may not include a sufficient number of machines, for 
which reasons he will clean his wheat in a wasteful way. He will not 
only take out stock which belongs to the wheat, but will leave in that 
wheat impurities which should be removed. There is material for offal 
in one part of the country which does not exist in another; for instance 




GRADUAL REDUCTION MILLING. 


83 

cockle. For the reasons here given, it would hardly be in order to give 
statements of the probable amount of offal which would be removed 
from the wheat. The conditions are so variable that nothing which 
could be said would have general application. 

The offal from the reductions and separations varies in quantity and 
quality with the yield. During the earlier times of millstone milling the 
effort was to clean the bran at the first reduction of the wheat, and it was 
only during the later years of that process—a few years previous to the in¬ 
troduction of the new process methods—that any large number of mill¬ 
ers reground the bran. It was not an unusual thing to hear it said among 
millers that they did not propose to make Hour out of bran, that they 
would grind wheat and not bran, and all that. They would say that 
the bran was worth as much as the low grade flour, and often this was 
said without figuring to test the accuracy of the statement. The divid¬ 
ing line between feed and low grade flour should be fixed by the price 
of both products. When feed is the same price as flour there is no need 
of milling it farther. At the same time that the feed is milled it should 
be borne in mind that it may be done so closely, so much of it may be 
pulverized, that it will depreciate the low grade flour to a very consid¬ 
erable extent, and to an extent which would render the operation un¬ 
profitable. Bran may be successfully reduced and cleaned profitably as 
long as the product of each reduction will sell for more than the feed. 
Now, it might be unprofitable to run the product of the various bran 
reductions or feed reductions together. The lower product of flour 
would contaminate the higher product, but there is no reason why the 
higher and lower products of low grade flour should be all run together 
as has been explained elsewhere, and for this reason bran may be cleaned 
according to the dictates of the market. 

The red-dog feed may be the cause of a great deal ol loss to the 
miller. It is more common to speak of clean bran than of clean red- 
dog feed. There are more and greater losses through carelessness in 
the cleaning of the red-dog stock than there is in the cleaning of the 
bran, for the reason that it is readily perceptible in the latter, while a 
great deal of stock may pass over in the red-dog feed without being no¬ 
ticed. 

Some few years ago, the -Millers* National Association oiteied a piize 
of a thousand dollars for the best bran compressing device. Such a 
machine would make it possible to export bran to the other side of the 


8 4 


GRADUAL REDUCTION MILLING. 


ocean—to Great Britain and the Continent. The carrying charges would 
be less both in this country and abroad. The value of the product of mills 
everywhere would be enhanced because of the higher price which would 
be received for that product on account of the lower freights on the offal. 

A satisfactory machine for this purpose has not as yet been devised. It 
is an open problem, but one which will certainly take practical form in 
the course of time. The packing of bran would be a great help to 
American millers, as would anything which would enable them to market 
their products at a higher cost than at present. Another way in which 
the packing of bran will help American millers will be that it will not 
only help them to get rid of their offal at better prices than they are 
now getting, but it will also make a better market for their flour in the 
countries to which it is exported. It is known that many of the mills 
abroad realize their only profit from the offal, and if we step in with our 
bran and mill feed we cut them out of this profit, and in that way cut . 
down their milling capacity and make room for our own flour. 

Broad, clean bran is an indication of good milling. It means clean 
flour and clean feed. If the bran is badly cut up, and is in small 
pieces, it is a fair indication that a dangerous proportion of it has been 
pulverized and distributed through various grades of the hour. Broad 
bran suggests that the grinding has been well done, that the break hour 
is clean and bright, that the middlings were easy to clean, and the bran 
easily finished on the last reduction. An examination of the bran is 
often a key to the whole grinding. It shows the whole thing at once. 

While speaking of bran and feed, other matters pertaining thereto 
come to mind, but which are not associated with the above subject. It 
has been noticed that people in looking at bran would squeeze it and 
toss it up in their hand and say: “Well, what do you think this will 
weigh?” We are always compelled to say, “we don’t know. ” But from 
motives of curiosity the trouble has been taken to ascertain. Those 
who would ask the question as to weight would have in mind the matter 
of yield ; but the yield cannot be judged by the weight of the bran or feed. 
In experiments as suggested above, it was found that the bran weighed 
fifteen pounds to the bushel, and that the same bran could be cut up so 
that it would weigh thirty pounds to the bushel. This was done by run¬ 
ning the same finished bran through a bran roll which was set up very 
close. Afterward the-Hour was sifted out and the bran weighed with the 
above result. The red dog feed, which was entirely red, with no si^ns 




35 


GRADUAL REDUCTION MILLING. 

of flour, would weigh more after it was ground than before. It is quite 
clear that the weight of bran and feed does not signify much in regard 
to the yield. A still more convincing proof is that in one mill, where it 
is with difficulty that the desired weight of feed can be gotten into a car, 
the yield may be slightly higher than in another where the bulk is much 
less. 

There are found in the market three kinds of offal—bran, fine feed or 
shorts, and finished or feed middlings. The fine feed or shorts contains 
very fine bran and red and woolly fibre, while the feed middlings are of 
a reddish gray color, and the richest feed from the mill. It contains 
bits of middlings, small pieces of nubby bran, that is, bran with a small 
portion of adhering middlings, and perhaps some flour. Now, it is these 
finished or feed middlings to which objection is made; they do not be¬ 
long in the feed pile. There should be two kinds of feed, bran and red 
shorts, or fine bran. Anything which goes to make the feed middlings 
look white or gray can be made into flour that is worth more than the 
feed. If the feed is white or gray, that is a sure sign that there is flour, or 
flour making properties, in it. Some will say that if this kind of flour 
is run into low grade it will reduce it so low that it would be better policy 
to run it into the feed pile. All this flour would not be so low, though 
a part of it would. That part should be taken out and barreled by 
itself. If it is not desirable to put in a packer for this extra grade, it 

can be run into sacks and run out once or twice a week. The great 

« 

waste of high yields comes from this grade of feed. 


CHAPTER XV. 


THE QUESTION OF YIELDS—BUHR AND ROLLER YIELDS COMPARED—YIELDS 

FROM CLEANED WHEAT THE MACHINERY OF THE MILL LIMITS THE 

PRODUCTION OF CLEAN FLOUR AND CLEAN FEED IN THAT MILL COM¬ 
PARISONS OF YIELDS UNDER THE OLD AND THE NEW SYSTEMS-CALCU¬ 

LATIONS OF PERCENTAGES—YIELD AND PERCENTAGE CALCULATED TO¬ 
GETHER. 

The question of yields is an interesting one. Uncertainty and doubt 
on this question may well be called the skeleton in the miller’s closet. 
An uncertainty in this matter is wearing and depressing. Many millers 
take a yield every day by weighing the feed and counting the Hour. 
Estimating the invisible or unaccountable loss as eight pounds per bar¬ 
rel, if a miller were to make 6,600 pounds of feed and 100 barrels of 
Hour, it would indicate that he took four bushels and thirty pounds of 
wheat to make 196 pounds of Hour. The writer knows of at least one 
mill which is arranged to weigh the wheat before and after cleaning, and 
the feed at the end of each day. This, together with the packer regis¬ 
ters, gives exact and reliable information. It appears to the writer that 
a miller could run such a mill with an easy conscience. He could be 
sure of himself every day. Such an arrangement would not only give 
the exact yield of Hour and pounds of feed, but would also show the 
invisible loss from day to day and suggest means of reducing it. Auto¬ 
matic scales are used in some instances to take daily yields. How re¬ 
liable they are cannot be said. A daily yield is a good thing to have. 
It locates responsibility. It points out the times of loss in such a way 
that they never can be of long duration where proper energy or skill 
is displayed. 

The writer has made lower yields on a buhr mill than he was ever able 
to make on a roller mill. It has been said that the difference in 
yield between the two is a mere matter of detail; that is, by rolling far 
enough and often enough as low a yield can be made on rolls as on buhrs. 
However, the writer cannot agree with this statement. It appears that 
there is a limit to the profitable reduction of certain grades of stock by 





GRADUAL REDUCTION MILLING. 


87 


smooth rolls; that, after being rolled a certain number of times, it reaches 
a state which is calculated to resent the smooth roller action. At this 
point millstones or scratch rolls become necessary. 

One often meets this question as to which will make the best yield, 
rolls or stones. Rolls will make a better flour from a low grade of 
stock than buhrs, or as they can go further into the wheat and still main¬ 
tain the difference in price between the flour and the feed, but it is evident 
that they will make the best yield up to the point mentioned; that is, 
they will put a larger portion of the wheat into a more valuable form than 
the stones. The fact that a miller does not make as good a yield on his 
gradual reduction mill as he did on his buhr mill does not prove anything. 
There was a controversy in a prominent milling paper a few months ago 
in regard to yields, which brought many millers with high yields to the 
front. Such yields as were talked about, from four bushels and forty 
pounds to four bushels and forty-eight pounds, are wasteful on winter 
wheat. A yield of four bushels and thirty pounds, on an average crop 
of wheat, counting it as it comes from the cars or wagons, should be the 
maximum per barrel. 

Millers are not inclined to talk publicly about yields, more especially 
those made at or near the time at which they are speaking, though many 
are willing to indulge in a little reminiscence. There is no great diffi¬ 
culty in keeping roller yields as low as four bushels and thirty pounds 
per barrel. With buhr milling, previous to the change to rolls, there 
was no more difficulty in keeping below four bushels and twenty pounds, 
and the writer calls to mind yields which varied from four bushels and 
eleven pounds to four bushels and fifteen pounds. These figures are 
given for the purpose of making the comparison and illustrating the 
statements which are to follow. The difference between a yield of four 
bushels and twenty-four pounds and four bushels and thirty pounds is not 
so great as affecting the cost of the flour as it is often counted, as it 
may be entirely owing to a larger yield of low grade flour, and not to a 
proportional increase in the percentage of other grades. In such a case 
—that is, when the yield is made by the increase in the amount of low 
grade—the 4-24 yield would be better than the 4-30 yield only by the 
difference in amount and quality of the low grade flour. The output of 
high grades would play no part in the matter. The difference between 
the 4-11 and the 4-15 yields which were mentioned, was made entirely 
in the low grade flour. The absolute amount of high grade was not 


88 


GRADUAL REDUCTION MILLING. 


changed, though the registers indicated that there was a smaller pro¬ 
portion. 

Yields are sometimes calculated from cleaned wheat, but as wheat is 
not bought in that condition, that way cannot form a safe basis. There 
are limitations as to the yield of a mill arising‘from its arrangement. 
There are always points beyond which it is not safe to go in the en¬ 
deavor to make flour at a low cost without corresponding changes in 
the amount and arrangement of the milling devices. Such arrange¬ 
ments limit the possibilities of the percentages and yield, and it is not 
safe to go beyond these limitations. In fact, it is sure to result in harm. 
In the effort to crowd a mill beyond its possibilities, low grade prod¬ 
ucts must of necessity become mixed with high grade Hour. In this 
way one may lose money by getting the yield too low, as well as by 
going to the other extreme. When a miller reaches the possibilities of 
his mill in producing high grade Hour, he can only better his yield by 
an increased quantity of low grade, and there is a good chance to hurt 
something here, as it should be remembered that pulverized bran is not 
necessarily flour, even if it will go through No. 14 cloth. 

There is no doubt but that under present methods, taking the whole 
country together, more wheat is being used to make a barrel of flour than 
with the stones. This does not argue that it takes more wheat by one 
system than it does by the other, but it does argue that the mills at large 
are very incomplete, and that a great deal of stock is run into the feed 
pile which might be run into the flour, and for two reasons: First, an 
insufficient number of reductions on all grades of stock, which means 
an insufficiency of machinery; and second, overcrowding the machinery 
in use and trying to get too much stock through the mill. There is 
hardly a mill in the country whose capacity is not overestimated or over¬ 
worked. Mills which should not make over 75 or 100 barrels, are called 
150-barrel mills, and very often crowded to that point. There are many 
mills labeled at 500 barrels capacity which cannot go above 400 without 
excessive waste; yet they are very seldom allowed to run down to that 
figure. A few trials and a little calculation will show the correctness of 
these statements. 

Until a mill has a fixed grade, an exact quality of wheat to grind ? 
it cannot have a fixed running capacity. Hard, dry wheat can be 
ground much more rapidly and at the same time finish the feed 
much better than soft, tough wheat. The character of the stock 

V 


GRADUAL REDUCTION MILLING. 89 

going into the feed pile determines the quantity of the feed to be 
put on a mill, and by varying it on the same grades of stock, the differ¬ 
ence in profits therein can be readily realized. The idea that it does 
not take more wheat to make a barrel of flour on the gradual reduction 
system than by die stone system is exemplified, as is believed, in the mills of 
Minneapolis. There the general principles were worked out early, and 
during the last months and years the details have been looked into care¬ 
fully, and such additions made as to make the mills more nearly complete 
than in any other place in the country. No doubt there are as good mills 
outside of Minneapolis as there are in it, when considered with reference to 
the quality of the work, but it is fair to say that Minneapolis is representa¬ 
tive of the best milling in this country. The right kind of men got hold 
of the business in the start, and, taking it altogether, the mills, the 
buildings, the workmanship and the quality of the help, there can be no 
doubt in the mind of any one as to the superiority and position of lead¬ 
ership which these mills and their millers occupy. These mills have 
been gradually reducing their yield for some time past, until it is now 
lower than it has been for years. 

There was published at one time a statement that the mills of a certain 
city were averaging about four bushels and forty pounds of wheat to a bar¬ 
rel of flour. This is not mentioned with particular reference to that city, 
but merely as a statement which represents average yields. There was a 
time, no doubt, when they used less than this amount, but not since 
they have been using the roller system. In future it will no doubt be 
much lower. Instances have been known where the yield was men¬ 
tioned on the basis of cleaned wheat, but this cannot be right, as the 
cleaning machinery is a part of the mill, and its work is included in the 
general milling operations, and anything which is taken out is as much a 
part of the offal as the bran or other feed. 

After all, the calculation on percentages should be made with refer¬ 
ence to the quantity of wheat used, and not the amount of floui packed. 
One miller may pack 35 per cent, of patent, as based on the packer 
registers, and another may make 30 per cent, on the same basis, and 
yet by making a lower yield the latter gets a better percentage of patent 
out of the wheat. That is, one man will make 3° cent, of patent, 
as estimated by the registers, and throw a certain percentage into the 
feed-pile which is not registered, while another miller will barrel this 
waste and calculate his percentage accordingly. The calculation o 


9° 


GRADUAL REDUCTION MILLING. 

percentage, to be of value, should be associated directly with the yield. 
If a small percentage of low grade, or a large percentage of high grade, 
is indicated by the packer registers, it is significant of good milling only 
when taken in connection with the yield. 

As said before, it is often the case that low yields are made by making a 
large percentage of low grade flour. The difference between a yield of 
four bushels and twenty-four pounds and four bushels and thirty pounds is 
not so great, as affecting the cost of the flour, as is accounted. The 
writer has seen the calculation carelessly made in this way, that the 
difference between 4.24 and 4.30 was six pounds, and that, with wheat 
at ninety cents a bushel, this would make a difference of nine cents in 
the cost of the flour. This is not correct, as it is entirely possible 
that this six pounds’ difference may be in low grade flour, worth, say, a 
cent a pound; and then there would be added to the quantity of feed 
this six pounds which was lost in flour. With the feed at one-half 
cent a pound, there is three cents which is not lost. Instead of losing 
the wheat, which was nine cents worth of stock, we merely threw stock 
worth six cents into the feed, and then, as feed, we got three cents for 
it. Therefore we lose only three cents, instead of nine. 

There should be means for taking a yield every day, and, at the same 
time, of determining percentages, which latter operation is commonly 
done in a very loose way. If a miller sits down in the evening and 
figures up that he has made 25 per cent, of patent and 65 per cent, of 
clear and 10 per cent of low grade, he may have reason to feel satisfied, 
or he may not. A calculation of percentages means nothing unless 
taken in connection with the yield. Millers have been known to go 
along for weeks at a time, priding themselves on the low grade flour 
which they were making. If that were the point, the miller mentioned 
above is making 10 per cent, of low grade, and might run enough of it 
into the feed pile so that he would be making 5 per cent., and on this 
latter basis feel contented. 

It is hardly right to speak of yields and percentages in this distin¬ 
guishing way; that is, using them in a way to indicate a wide difference 
of meaning, when in fact there may be a percentage of flour from'the 
wheat, or the same idea may be expressed by speaking of the yield of 
flour from the wheat. It must be clear to all alike that the method out¬ 
lined is in every way preferable to the one in common use. Of course 





GRADUAL REDUCTION MILLING. 


9 1 


it is not possible to make a daily calculation of this kind in mills as 
commonly arranged. 

When yields are taken in the regular way, it is suggested that the re¬ 
sults be expressed in the way indicated below. As an illustration, the 
following figures are selected as expressing the percentages in the ordi¬ 
nary way: 25 per cent, for patent, 65 per cent, for clear, and 10 per 
cent, for low grade. 1 hen a yield of four bushels and thirty pounds 
per barrel is assumed. Eight pounds represents the unaccountable loss. 
Thus there are 270 pounds of wheat, 196 pounds of flour and 8 pounds 
of invisible loss. This, expressed in the form of percentage, makes the 
following showing: 

Per cent. 

For flour. 72.5 

For feed. 24.4 

For invisible loss. 2.9 


Total 


99.8 


To separate the different kinds of flour and make the same calcula¬ 


tion this table is made : 

Into patent flour. 

Into clear flour. 

Into low grade flour 

Into feed. 

Invisible loss. 


Per cent, of wheat. 

. 18.125 

. 47-125 

. 7-250 

. 24.4 

. 2.9 


Total. 99.8 

This shows the exact condition of things—yield, percentage and loss 
all taken into consideration in one calculation—and is the only way to 
put it and be exact. 

After taking the yield in the ordinary way, the percentage of each 
kind of flour can be used to form this valuable and instructive combina¬ 
tion. It will show many things which are not understood and appreci¬ 
ated. For instance, two or three yields expressed in this way will show 
just where the variation is effected. It may be that for one yield a lower 
exhibit in the amount of wheat used is made, at the same time a larger 
percentage of low grade is indicated, while the percentage of other 
grades may not be absolutely affected, though relatively they will be. 
This will indicate that the improvement in the proportion of flour to 
wheat, and the consequent decrease in the percentage of feed, is made 
entirely in low grade flour. 














9 2 


GRADUAL REDUCTION Mil,I.INC. 


Fearing that this explanation may not be altogether clear, this idea 
will be expressed in another way. A miller may make a better yield as 
far as the amount of wheat is concerned by going a little farther into 
his feed, but without absolutely changing the amount of other Hour 
made. Again, another calculation of this kind, at another time, might 
show that an improvement in the yield had been made by increasing the 
amount of patent Hour made, and without changing the amount of other 
kinds. Furthermore, a comparison of a number of these tables might 
show where the percentage of wheat, feed and loss were the same, while 
the value of the yields were widely different, owing to the varying pro¬ 
portions of the different kinds of flour. Thus, while the main propor¬ 
tions might be the same, a larger proportion of patent and a correspond¬ 
ing decrease in the other grades would indicate the better yield. 

An accurate knowledge of the percentages which would be given in 
the way shown would develop the weak points, or rather show the weak 
points, in the mill or the millers. There would be fewer opinions based 
on prejudice, and the exact value of every milling machine would ulti¬ 
mately be determined according to an incontrovertible standard. There 
is nothing known which is better for millers and mill owners alike than 
daily yields. It is believed that the time will come when such yields 
will be as common as the weighing of wheat now. The very profit¬ 
able milling of several years ago developed careless habits in all these 
matters. There were millers who did not take a yield once a year; in 
fact did not know how much wheat they were taking at any time. Now 
that times are closer, there is less carelessness in this respect, there be¬ 
ing few millers who do not have a tolerable knowledge of how much 
wheat they are using. As prosperous times made millers careless, the 
closer times will make them careful. 

If one were to say that he meant, when using the word “yield,” the 
amount of wheat used when making a barrel of Hour, he would cover 
the ordinary idea on this subject. But there is a broader definition of 
the word as applied to milling. It means money, after all, and the mill 
which yields the most money per bushel of wheat is doing the best work. 
It does not necessarily follow that he who is making a barrel of flour out 
of the least wheat is making the most money. It is entirely possible to 
make 196 pounds of stock which will go through a Hour cloth out of, 
say, 210 or 212 pounds of wheat; that is, making this allowance of from 
fourteen to sixteen pounds for loss which cannot be accounted for, and 


GRADUAL REDUCTION MILLING. 


93 


perhaps a little feed. Now, it should be remembered that the fact of 
stock having gone through a No. 12 or 14 flour cloth, does not imply 
that if a miller were to put so large a proportion of his wheat into the 
Hour packer as is above indicated, he would be doing the best possible 
thing in the way of a yield, for the reason that the miller who is making 
proper a more intelligent separation by running that which may be called 
Hour into the hour packers, and that which is properly feed into the feed 
bin, is making the best yield, in that he will get more money out of his 
wheat. 


CHAPTER XVI. 


UNIFORMITY OF FLOUR AS A VALUE GIVING ELEMENT—THE EFFECTS OF 
WHEAT ON THE UNIFORMITY OF FLOUR—’REDUCTION OF HARD AND SOFT 

WHEAT-THE SIZE OF WHEAT-THE MOST THAT A MILLER CAN DO FOR 

HIS FLOUR—WHEAT HEATERS AS CONTRIBUTING TO UNIFORMITY- 

SMOOTH ROLL REDUCTIONS-SIZING ROLLS. 

Any one who knows anything about the sale of Hour knows that the 
Hour made by a miller who has the reputation of making a uniform 
grade as to quality will command a price based on this uniformity as 
well as on its actual value. A flour may not be exactly the best flour 
which goes to a certain market, yet it may command the best price, or 
a price above that of flours of similar but uncertain quality. The view 
taken of this matter will not be a trade view, only in so far as anything 
which pertains to the manufacture of flour has to do with the trade. It 
is a manufacturing view. There are many things—many conditions— 
which may alter the grade and alter the uniformity of the same. 

First and foremost there is the wheat, and it may be said that wheat 
has a myriad of sins on its shoulders which do not belong there. It 
sometimes happens that a miller neglects his mill during the night and 
there is bad flour in the morning, and it sometimes happens that he says 
that the wheat is to blame. When reports come from the East that the 
flour is working badly, the wheat is often blamed. 

A miller cannot always have a uniform grade of wheat, even if it be 
of the same general variety. It has been said that if the miller always 
had a uniform grade of wheat and if the laces did not break, if the grind¬ 
ing did not require changes, he would be paid the same as a roustabout. 
It is the business of the miller to make such changes in his mill as to its 
running, its grinding and bolting, as are suggested by the size, texture 
and characteristics of the wheat. With soft wheat it is often required 
that the grinding be closer on the first and second breaks and rather 
open on the third, fourth and fifth. This will make round, sharp mid- 




GRADUAL REDUCTION MILLING. 


95 


dlings. On the other hand, with hard wheat, the grinding may be more 
open on the first break, and in event of the bran being dirty, the same 
relatively high grinding may be preserved to the last. 

Soft wheat will require more cloth and coarser cloth than hard wheat. 
Soft wheat flour may have larger granules than that from hard wheat and 
yet not be so sharp in feeling. Flour bolted through a 9 or 10 cloth 
where the wheat is soft will not feel as sharp as when bolted through a 
12 or 13 cloth with hard wheat. For this reason it is important that the 
bolting apparatus be so arranged that the flour may be taken, in whole 
or in part, through fine or coarse cloth, as circumstances may suggest. 
There are two ways of doing this. The coarse cloth may be at the 
head, as is usual, and the finer cloth below, by which means all material 
going through the coarse cloth may be re-bolted below; or this same 
arrangement, as to the coarseness of the cloth, may be reversed, and 
the last or bottom reel may be clothed with coarse cloth. For such an 
arrangement the reels above should each be clothed at the tail with 
scalpers of increasing fineness, which will bring the material to be bolted 
on the last reel or reels of a quality to be readily converted into clean, 
bright, sharp flour. 

There will be times when the wheat is very hard that this will not be 
used at all, but it is not necessary that the flour should be bolted through 
a uniform cloth to be uniform in feeling as to its sharpness. The sharp¬ 
ness of flour is determined as much by its hardness as by its size. The 
granules may be large and soft and yet not feel sharp, or they may be 
hard and small and yet possess all of the granular elements of good 
flour. 

Hard wheat, of course, makes more middlings than soft wheat; yet 
the effort to make a uniform proportion in either case will be in the di¬ 
rection of uniform work. The same grinding which will make round, 
sharp middlings out of hard wheat, will make soft, clammy, flat mid¬ 
dlings out of soft wheat, and middlings which cannot be purified. With 
hard wheat the reductions can be more uniform in the amount of work 
done from the first to the last break. With soft wheat a larger propor¬ 
tion of the work of reduction must be done on the first two or three 
breaks, more particularly the first two. which, followed by higher giind¬ 
ium, will make large, round middlings, with clean bian on the last bieak, 
together with distinct separations of the branny from the floury poitions 

of the wheat. 


9 6 


GRADUAL REDUCTION MILLING. 

The size of wheat exerts a marked influence in the operation of the 
mill. A change from large to small wheat of the same quality and 
variety, as often happens, will largely increase the feed on the mill, and 
give relatively higher grinding, which would work a marked influence on 
the separations. On the other hand, the change from small to large 
wheat cuts down the feed and makes the grinding relatively closer, and 
whereas the stock on the reels may not be so heavy, it is quite soft. 
The change in grinding may not be so disastrous to the break Hour as to 
the middlings and middlings flour, which are small in volume and soft 
in character. Thus such changes in the wheat require corresponding 
changes in the grinding to maintain uniformity in the product. 

No miller can battle against unsound wheat; therefore it is somebody’s 
business to keep unsound wheat out of the mill. Carelessness in this 
respect demoralizes the interest of the help. The miller cannot and 
will not take an interest in his milling when, in the midst of smooth 
sailing, he is liable to run against a car of unsound wheat. A uniform¬ 
ity of flour cannot be preserved with widely varying grades of wheat of 
the same variety, yet the proportionate difference is not the same by any 
means. There may be a wide variance as to the texture, and for all 
marketable purposes no marketable difference. The methods for reach¬ 
ing such a result were shadowed in the above suggestions. 

On general principles, all that a miller can do for his milling is to 
maintain an even granulation of products of uniform brightness. If a 
flour is bright and granular, that is all a miller can do for it. He cannot 
impart strength which is not in the stock. After all is said and done, 
the most skillful grinding and manipulation can give only an approxi¬ 
mately even granulation. This lack of uniformity can be partially 
reconciled by the subsequent smooth roll reductions and sizings, separa¬ 
tions and purifications. 

With reference to the uniformity of products, it is proper to speak of 
the wheat heaters. They contribute largely to the uniformity of the 
character of the wheat, and they are wonderful in their ability to main¬ 
tain a uniformity in the color of the flour. 

Having mentioned the breaks and canvassed the first operations on 
the wheat, more remains to be said in regard to separations. No re¬ 
duction system or system of grinding, no matter how well the grinding 
may be done, can atone for the deficiencies of the separating system. 
The reductions are important, and good grinding is necessary, but they 







GRADUAL REDUCTION MILLING. 


97 


cannot be so complete as to override deficiencies in the bolting and 
purifying. 

In regard to the smooth roll reductions, there are very few mills of 
any class where most of the smooth rolls are not overworked, and in 
many mills they are not used for grinding, but rather for mashing. The 
smooth iron rolls should never be run so close as to flake the stock. 
Where it is flaked the work is mashing and not grinding. In the reduc¬ 
tion of any grade of material, such a reduction should only be carried 
as far as sizing and breaking, but not mashing or flattening. 

Where the grinding is done as suggested, there is a margin of sharp¬ 
ness, a difference in granulation which will admit of variations accord¬ 
ing to the quality or consistency of the material handled, thus admitting 
of wide changes or differences in the quality of the product. The ma¬ 
terial to be ground or sized can be touched lighter—ground higher— 
when it is from soft wheat, and at the same time bolt cleaner and whiter 
than if it were from hard wheat. Hard wheat can be ground closer and 
still not fiake. For this reason mills which are continually operating on 
soft wheat require more rolls and more reductions than those which are 
operating on hard wheat. On the other hand, the capacity of the mill 
cannot be so great when grinding soft wheat as hard. Unless the grind¬ 
ing is properly done in the first place, there can be no proper variations 
according to the material handled. The grinding has to be correct for 
one quality of stock in order to be incorrect and require changes for 
another. 

Sizing rolls proper, that is, those which are used for breaking down the 
large middlings, require the greatest care and the most delicate manipu¬ 
lation of any of the machinery in the mill. The difference in quality 
and quantity of the stock is more marked here than at any other place. 
Furthermore, the middlings from the sizing rolls are of the highest grade, 
and any deficiencies there mark the entire product of middlings flour. 
As is well known, the reduction of the amount of feed on these rolls with¬ 
out a corresponding change in the set of the rolls themselves will make the 
grinding closer, and vice versa) and of course if it is right for one it is 
wrong for another. If the middlings are sized too closely they will be 
flat and soft, and if not close enough the product will be red and ragged 
and the tailings rich. Millers have more to learn about the sizing of 
the middlings than anything which is to be met at this time. 


(7) 



CHAPTER XVII. 


THE DIFFERENT CLASSES OF REDUCTIONS-A GENERAL CONSIDERATION OF 

THE VARIOUS BREAKS-REDUCTION FOR MIDDLINGS PURIFICATION- 

DISINTEGRATORS ANTAGONISTIC TO GOOD REDUCTIONS—RELATIVE 
SEVERITY OF VARIOUS REDUCTION MACHINES. 

According to present methods there are four classes of reductions— 
one for middlings making, one for middlings purification, one for mid¬ 
dlings reduction, and a fourth tor the cleaning of feed. In speaking of 
the first class, which refers to middlings making, it may be said that this 
reduction is made with reference to purification in the first place, and to 
clean offal in the second. It so happens that these two conditions are 
not antagonistic, as the same grinding which will make round, sharp 
middlings and those which are reasonably f r ee from bran and other im¬ 
purities, will leave the bran proper in a condition to be readily cleaned. 
That is, it will be broad and flat, which is the best possible condition 
from which to get the best Hour and the cleanest feed. Being in large 
Hakes, it is not so liable to be cut up and pulverized in the final reduc¬ 
tion as when it is ground fine in the previous process of grinding. 

The kind of grinding which makes this desirable bran stock, also 
brings the middlings into the best condition for purification, as suggested 
before. One way of reaching this result may be outlined by an analysis 
of the different breaks. 

There is much less Hour made on the first break than is generally 
supposed. The writer’s experience with winter wheat is that the amount 
of Hour on this break is not proportionate to the closeness of the grind¬ 
ing. One may set these rolls where he thinks they are doing proper 
work, and if, for any reason, he sees fit to set them closer, the amount 
of Hour will not be increased in proportion to their closeness. This is 
because of the coarse corrugations, the size and quality of the product 
bearing a certain relation to the size of the corrugations. For instance, 
a set of rollers with twenty-four corrugations will make a larger propor¬ 
tion of flour and fine middlings than rolls with eight or twelve or other 
coarser corrugations, even though the stock be the same size. The 






99 


GRADUAL REDUCTION MILLING. 

spacing of the corrugations, to a certain extent, therefore, influences or 
regulates the proportion of fine products of the reduction. 

The second break more seriously commences the work of middlings 
making, though this, as well as the first, is more of a preparatory process 
than otherwise, each doing its work of sizing and opening the grain for 
the subsequent reductions. 

The first break is more of a direct purification method than the fol¬ 
lowing wheat breaks, in that a proportion of deleterious material is 
removed directly after this break. The second break makes large, 
coarse middlings and a small proportion of flour. The grinding on these 
two breaks has more to do with the ultimate condition of the bran stock 
and the quality of the middlings than do the three following breaks, the 
two former acting more directly in the preparation of such stock. If 
the wheat is soft, the first two breaks can be run closer, and the three 
following breaks more open than when the wheat is harder. The reason 
for this is that close work at first on the hard wheat breaks and shatters 
the bran more than it does when the wheat is softer and the bran 
tougher. The kind of grinding which makes the best middlings with 
either kind of wheat, makes the best bran stock. Closer grinding at first 
on the soft wheat admits of more open grinding on the third, fourth and 
fifth reductions. This makes desirable middlings, which have a very 
small proportion of detached or adhering bran. The more open grind¬ 
ing on the first two breaks on hard wheat may require a little closer 
grinding on the subsequent reductions in order to reach the desired end. 

The products of the third and fourth breaks are near enough alike to 
admit of treating them together. The fourth is really a repetition of the 
third, though, of course, the product must be slightly lower in quality 
and smaller in size, proportionate to the difference in the grinding and 
the corrugation of the rolls. The similarity is that the stock is more 
nearly of the same class than that of any of the other reductions. It is 
here that the best and largest proportion of middlings is made and flour 
next to the purest. 

The fifth reduction is decidedly on the downward grade. The mid¬ 
dlings are small in size, the flour white enough, but accompanying this 
product before the separations are made, is a large proportion of long, 
hairy looking bran. It is on this break that the bad work which came 
before it shows up, in the production of this dangerous woolly stock. 


I 


IOO 


GRADUAL REDUCTION MILLING. 


The sixth break, which is most commonly the finishing process, can 
not be very bad with ordinary care, when the stock has been properly 
prepared for it. There are no middlings from this break worthy of being 
handled on purifiers. The flour Irom this break shows very red and 
dull in the dough, but makes comparatively a better appearance in the 
dust. This flour is too good to go in with the red dog, and when the 
feed therefrom is properly cleaned, it is not good enough for the bakers’ 
or clear flour. It will grade, even when the bran is properly cleaned, 
•equal to a St. Louis XXX, or a good New York Super. Therefore, the 
only thing to do with this grade of flour is to run it by itself or with 
flour of corresponding grades from the lower smooth roll reductions. 

It is common to run the second, third, fourth and fifth break products 
togedier. This is necessary in small mills, but is not conducive to the 
best results. 

The second class of reductions mentioned was for the purpose of puri¬ 
fication. The products of the process of middlings making are middlings, 
flour and bran of various degrees of purity. After the bran is disposed 
of, there are the middlings, the flour, and the contained impurities. The 
flour being disposed of, all that remains is middlings, more or less pure. 
There are many grades which contain such a large proportion of dele¬ 
terious matter that the ordinary purifier cannot appreciably help them. 
It appears somewhat out of place to speak of some of the lower roll 
stocks as middlings, yet they are neither bran nor flour. They are too rich 
for the former and too large for the latter. Such stock is really a low r 
grade of middlings. 

The smooth rolls and the separations which follow is one method of 
purification which belongs in this classification. Such rolls are, more 
often than otherwise, looked upon and used more as reduction agencies 
than as methods of purification. The smooth rolls are very important 
and useful in the purification of the larger grades of middlings. They 
are not appreciated for such use, but when it comes to handling mid¬ 
dlings which we do not think it worth while to put on a purifier, their 
work is invaluable. They are the only machines which will appreciably 
aid in purifying this grade of stock. 

While on this point it is well to say something about detachers and 
disintegrators, which are frequently used to follow the smooth roll re¬ 
ductions for the purpose of shaking up or detaching the smooth roll 


GRADUAL REDUCTION MILLING. 


IOI 


stock. This is one thing which a miller does not want to do. The 
material goes on to the rolls for the purpose of making a separation, for 
purifying the stock, which allows it to be readily separated from the 
unbroken impurities. In some instances the impurities are flattened at 
the same time that the middlings are broken, and thus the separation is 
more distinct and marked. A detacher which breaks and tears to 
pieces the impurities, renders purification impossible. And whereas the 
rolls are efficient in purification without the disintegrator, they are mere 
reduction machines with it. The disintegrators are mixers, and spoil all 
the good work of the roll. Their use is often thought to be necessary 
on account of the stock being flaky, but this is no excuse at all, as the 
flakes are wrong in themselves. There is no reason why the reduction 
should be so close as to make the stock flaky. Smooth rolls should be 
used for breaking or sizing, and not for grinding or mashing. The flour 
cannot be clean or bright where the stock is squeezed and the impurities 
thus pulverized. Often when stock from smooth rolls looks foxy, the 
miller will try to bring up the flour by shortening up on the flour con¬ 
veyor, which throws over a lot of soft stock to the next reduction and: 
separation, and at the same time does the flour little or no good. If,, 
under such circumstances, he should merely grind a little more open, he 
would find the flour bright and sharp, the tail thin and poor, and the 
cut-off sharper and cleaner, thus giving the following rolls less to do. 

The work of purification is brought about in the larger middlings not 
only by changing the relative size of the pure middlings and the impu¬ 
rities, but by changing the relative specific gravity of the two parts, as 
well as by making a positive separation of the impurities from the mid¬ 
dlings to which they are directly attached. 

Of the different classes of reductions mentioned, the third was with 
reference to the reduction of middlings to flour. In either of the 
classes of reductions mentioned, the flour is made incidentally. The 
making of flour in the middlings making is what the miller does not 
want to do, as it goes into lower grades and commands a smaller price 
than when retained in the form of middlings for purification, and their 
ultimate reduction to pure Hour here implied. The reduction to flour 
may be by smooth iron rolls, porcelain rolls, scratch rolls or millstones. 
The question of the relative efficiency of each is a mooted one. The 
severity of the reductions are represented on one extreme by the mill- 



102 


GRADUAL REDUCTION MILLING. 

stone as being the most severe, and on the other by the smooth iron 
roll as being the most gentle, the porcelain and scratch rolls occupying 
intermediate positions, the latter coming next to the millstones in sever¬ 
ity. In order to reach the same result, that is, the same quality of flour 
by the various reduction methods, the middlings have to be differently 
prepared for each. For instance, the millstones would do the best work 
when the middlings are of a small, uniform size. 


CHAPTER XVIII. 


THE CLOTHING FOR SCALPERS-THE RELATION OF THE CORRUGATIONS TO 

I HE SCALPING NUMBERS-THE DEVELOPMENT OF THE PROPER SCALP¬ 
ING NUMBERS FOR THE VARIOUS BREAKS-THE PROPER STOCK TO TAKE 

THROUGH THE SCALPING CLOTH ON THE BREAKS—FINER CORRUGATIONS 
ON SMALL MILLS-LENGTH OF SCALPERS FOR VARIOUS BREAKS. 

We all know that the clothing of the scalpers begins by making 
the first one the coarsest and the last the finest, with intermediate grada¬ 
tions. 'Phis is made necessary, in the first place, by the size and 
character of the material to be reduced, and secondly, by the size 
of the corrugations which perform these reductions. As to the size 
of the grain, it is easy to see that the largest middlings can be taken 
from the whole grains or from large parts thereof which include the 
full thickness or size of the ins : de of the wheat berry. For example, 
larger middlings can be taken from a whole or a half grain of wheat 
than from the material going to the fifth or sixth break, which con¬ 
tains only a small proportion of middlings stock. Thus the largest 
middlings will naturally be taken from the largest stock, or from stock 
which contains the material from which middlings are made in the largest 
sized pieces. In the second place was mentioned the size of the corru¬ 
gations as influencing the numbers of cloth on the scalping reels. No 
one can intelligently determine these numbers without knowing the cor¬ 
rugations to be used for the various breaks. The stock being of the right 
character for the various breaks, the size of the corrugations will deter¬ 
mine, to a large extent, the size of the middlings. For instance, if one 
were to use finely corrugated rolls for the first break, not nearly so large 
a proportion of large middlings could be made as with the coarser cor¬ 
rugations; and, as there is an abundance of stock out of which to make 
large middlings on the first break, it is fitting that the corrugations should 
be coarse, which implies that the scalping wire should correspond in 
mesh to the size of the middlings made. As the stock gets lighter, as 
the proportion of middlings on the wire decreases, proportionately finer 
corrugations are required. These two conditions together—that is, of 




104 


GRADUAL REDUCTION MILLING. 

the stock and corrugations—imply that there will be finer middlings, 
and as they are finer, the scalping numbers will naturally correspond. 

It should always be understood that it is desirable to remove such 
middlings from the various breaks as have no adhering particles of bran, 
and as such possibilities are indicated by the conditions named above, 
the scalping numbers should be arranged with reference t > such a result. 
Where they are too coarse it means that there is material to be handled 
on smooth rolls which could be more advantageously broken on the 
breaks following those from which such middlings were taken. Where 
such middlings are sized or reduced on the smooth rolls, it further im¬ 
plies that there is a large amount of coarse, branny material to be car¬ 
ried through the tailings rolls and subsequent reductions, which renders 
the work of finishing this material and the finer stock carried along with 
it much more difficult than it otherwise would be. Thus the advantage 
of arranging the scalping cloths so that the product of middlings will 
contain a minimum quantity with adhering portions of bran, is apparent. 
At the same time it is desirable that such clothing should’be coarse 
enough so that the entire product of desirable middlings may pass 
through the cloth rather than over the tail and to the next reduction. 

In the small roller mills which are now being built, which use only 
four or five breaks, the clothing of the scalping reels is finer as the cor¬ 
rugations are smaller and the grinding relatively closer. Furthermore, 
it is not desirable to have to handle large middlings in such mills as 
these, because everything being cut close as to the cost of the 
plant, there is not enough reduction and separating machinery to do 
full justice to larger middlings. For this reason in such mills the cor¬ 
rugations should be finer, with the intention of effecting the purpose 
above named; consequently the scalping reels would have finer wire 
or cloth. 

Another thing affecting the clothing of scalping reels is the character 
of the wheat that is ground. Soft wheat will make larger middlings 
than hard, brittle wheat, and large wheat will make larger middlings than 
small wheat, which otherwise has the same general characteristics. 

In connection with the breaks it will not be out of place to mention 
scalping reels, as a proper scalping is necessary for good reductions. 
The reels should increase in length or capacity as the breaks advance 
It is almost as important that they should not be too long, as it is that 
they should be long enough. When they are longer than is necessary 



GRADUAL REDUCTION MILLING. 


105 

to make the separation of flour and middlings from the coarser material, 
they make flour in the reel and force fine bran and other deleterious 
material through the wire cloth. If the reels are too short they carry 
over flour and middlings, which is wrong in itself, in that it reduces the 
middlings at an improper stage in the process, while the flour is carried, 
it may be, into grades where it does not belong. Again, the unreduced 
portions cannot be properly handled when mixed with material not re¬ 
quiring reduction. The following lengths of reels have been found to 
be satisfactory in a 400-barrel mill, viz.: First break, 6 feet; second, 
8 feet; third, 10 feet; fourth, 12 feet; fifth, 14 feet. For the sixth break 
a common form- of centrifugal reel six feet long may be used, clothed 
with 20 wire, the tailings of which reel go to the bran L in, while the 
product is again scalped on an 18-foot silk reel, where it is graded into 
three grades. 




CHAPTER XIX. 


\ 


SMOOTH ROLLS-SMOOTH ROLLS AS PURIFIERS-SMOOTH ROLLS AS RE¬ 
DUCTION MACHINES-THE PROPER SETTING OF SMOOTH ROLLS-THE 

THEORY OF DIFFERENTIAL MOTION EXPLAINED-THE EVILS OF EXCES¬ 
SIVE PRESSURE BY SMOOTH ROLLS-THE EFFECT OF DIFFERENTIAL MO¬ 
TION IN PRACTICE-THE EFFECT OF VARIATION IN DIFFERENTIAL 

MOTION-THE SETTING OF SMOOTH ROLLS TO REACH THE BEST RESULT 

-THE LIMIT OF THE REDUCTION POWER OF SMOOTH ROLLS-THE 

NECESSITY FOR MILLSTONES OR SCRATCH ROLLS. 

Smooth chilled iron rolls came into use in this country after the time 
of the introduction of the purifier. The value of smooth rolls lies in 
the fact that they are purifiers at the same time that they are reduction 
machines. They are the only reduction machines which will lend aid to 
the purification of the stock at the same time that their tendency is to 
reduce it. They reduce the dour portion, the portion which should be 
reduced, and at the same time flatten the germ and do not seriously 
disturb or disintegrate the bran, the fibre or other impurities. 

The perfection of this idea is the perfect reduction machine. How¬ 
ever, the smooth rolls are not perfect; they are not absolute purifiers. 
They approach more nearly the state of perfection as reduction ma¬ 
chines than do any other milling devices of this kind. 

The purification of middlings is not possible without the use of these 
machines. There are the large portions of wheat with adhering por¬ 
tions of bran, the pieces of middlings which cannot be removed from 
the bran on account of there being little or no difference in the specific 
gravity of the two products; then there is the fibre and the germ. The 
flour particles are easily disintegrated, and the bran and the germ and 
fibre are either flattened out, or remain undisturbed. There is a change 
made in the relative gravity of certain of the particles, and a change in 
the relative size of certain other particles. 

In the first instance, there is a change of relative gravity by the break¬ 
ing of the middlings into small particles, while the bran particles re¬ 
main the same size, and consequently of greater gravity than the 



GRADUAL REDUCTION MILLING. 


107 


middlings themselves. Then again, the change as to size is more clearly 
illustrated by the breaking of the middlings and the flattening of the 
germ. Not only are the middlings made smaller by the breaking, but 
the germ is made larger by flattening. All separations by smooth rolls 
are made on account of the relative size of the pure or impure particles, 
and their use must be considered with reference to bringing about such 
a change. The idea that they are mere reduction machines and not 
purifiers, limits their usefulness. 

A miller who buys a reduction machine merely for reduction purposes, 
need not waste his money by buying smooth rolls; he can get more re¬ 
duction per dollar by buying millstones or scratch rolls. 

New process and gradual reduction milling came about as the de¬ 
velopment of purification ideas, and the development of new process 
and gradual reduction machines has been in the line of purification. 
The miller reduces to purify, and he purifies that he may reduce further. 
Now, if he may reduce and purify in the same operation, he is following 
out the true principles of his business. Such a thing is possible with the 
use of the smooth rolls ; that is, when properly used. 

Absolute perfection and absolute purification is out of the question. 
There is no perfection, and there is no such thing as absolute purity. 
An agent of purification can only hope to make approaches toward per¬ 
fection. No one machine can do it all, and no one or no class of ma¬ 
chines can reach the limit of present possibilities. 

When we say that a smooth roll will purify, we mean in fact that it 
will help, that it will lend aid as a purifier, and we speak of the ordinary 
sieve and suction machine in the same sense—as a link in a chain, as a 
part of a process. If the miller has in mind that his smooth rolls are 
purifiers and will treat them as such, he will do better work with them, 
will handle them altogether differently than if he were using them as 
reduction machines. 

The miller who sets a pair of smooth rolls with a monkey wrench 
does not know that they are purifiers, neither does he who lets them 
run by friction with tight springs. The miller who allows the stock to 
come through the rolls in a flaky condition is not aware that the smooth 
rolls are purifiers. They perform this valuable office only when used 
carefully and intelligently. Absolute pressure on the stock does not 
reduce it, does not disintegrate it. It merely flattens it, hardens it. 

“Pressure will disintegrate only to a certain extent, beyond which it 




io8 


GRADUAL REDUCTION MILLING. 


produces increased solidity. It is therefore erroneous to suppose that 
middlings which are to be reduced by rolls should be subjected to great 
pressure. Neither is it true that pressure will hold the middlings against 
both rolls, as is necessary to effect the desired end.”— \_Dr. Sellnick.^ 

The same authority says in regard to the differential velocity of rolls: 
“The term differential velocity does not relate to the varying velocity 
of the revolution of the rolls, but is derived from the differential 
velocity of the circumference. ” By this is meant that two rolls of dif¬ 
ferent size may run at different speeds and still not have a differential 
velocity. Say we take a roll which is thirty inches in circumference, 
that is a little over nine inches in diameter, and run it against another 
roll which is twenty inches in circumference, or a little over six inches 
in diameter. Now, the larger roll might run 300 revolutions per minute 
and the smaller roll 450 revolutions per minute, still they would both 
travel the same number of feet as measured by the velocity of the cir¬ 
cumference. Both would travel 9,000 inches per minute, which result 
is derived by multiplying the circumference by the number of revolu¬ 
tions per minute. Differential velocity means an absolute difference in 
the number of feet traveled by the circumference of two rolls in the 
same length of time. 

Here is a cut of a drawing made by Dr. Sellnick wherein he illustrates 
the theory of differential motion. A is the slow roll, and B the fast 

roll; b will arrrive at b‘ while a is at a' and 
a arrives at x (a 7/ ) and b will be far be¬ 
yond at b". All points b move with 
greater velocity than points a. Fig. 2 
represents the action of differential 
motion on an elastic substance. The 

X 

body will be held at a b , and in its passage 
to a" b" (when a arrives at x and while 
b has arrived at b") it must stretch the 
distance a" b" and form a band like 
strip (a" b") in length. In the case of 
brittle particles the substance would be broken into small pieces. If 
there be no differential there will be mere compression and incidental 
integration. 

Dr. Sellnick tells how stock maybe calendered, that is, polished, made 
smooth and hard like a sheet of paper. Calendered paper is produced 







GRADUAL REDUCTION MILLING. IO9 

by differential motion, one roll running slow and the other running fast 
as to its circumferential velocity while the paper is held under great 
pressure. This makes a smoothing action—a compressing, polishing 
action. This is what the miller does when he sets his rolls very close 
and makes a hard, flaky stock. He has calendered middlings or calen¬ 
dered tailings, or even calendered red-dog. He has a sleek, glazed, 
compressed mass, and then he runs the stock through a mixing machine 
called a disintegrator, and pulverizes and tears to pieces the wafer¬ 
like stock in a way to derive no benefit from a smooth roll reduction. 
The impurities and all alike pass through the cloth and go into the flour 
;and reduce the price. Either reduce the profits or increase the loss to 
the mill owner. 

Smooth rolls to be run properly should be set for a breaking or disinte¬ 
grating action. They should not be allowed to compress the stock. 
The distance between one roller and the other should be such as to re¬ 
duce the size of the brittle particles and merely flatten to a slight extent 
the germ particles, but not necessarily disturb or compress the bran 
particles. If the latter has adhering particles ofpniddlings the action 
should be such as to break the Hour particles because of the differential 
motion, but there should not be a pressure such as to flatten the mid¬ 
dlings particles, or to break and disintegrate the bran particles. 

After stock has been once compressed it can never again be reduced 
without disturbing and pulverizing the impurities, for which reason we 
may say that many smooth rolls are improperly handled. 

Quite a difference may be made in the product of the tailings rolls 
by a change in the differential motion of such rolls. While the differ¬ 
ential is excessive the flour will be more ragged, it will feel longer, and 
will contain a larger proportion of deleterious material than when the 
reductions of such stock are made with a smaller proportion of differ¬ 
ential. The action of the differential motion of smooth rolls is to 
•elongate the stock. This quality or tendency is limited by the liability 
of the stock to break. If a piece of dough were passed through the 
-smooth rolls it would be flattened out, or elongated. The amount or 
proportion of elongation would be estimated by the differential motion 
of such rolls. The tendency of one roll to hold back and of the other 
to advance may be estimated by the excess of speed of one roll over 
another, and the elongating qualities on such a movement are exactly 
.in proportion as the difference in speed. It is evident that the break- 




I IO 


GRADUAL REDUCTION MILLING. 

ing action will predominate; that is, there will be more breaking than 
elongation in hour stock. There cannot be much elongation of mid¬ 
dlings or brittle material of that kind. It will be broken. There is a 
limit to the elongating qualities of all material which goes on rolls, 
whether it be impurities or otherwise. Where the differential is excess¬ 
ive, it is apparent that a certain large proportion of the impurities would 
be broken and pulverized by the differential action of the rolls. As an 
illustration of possibilities, we will say that the motion of the rolls be 
integral; that is, that there be no difference in speed. There will be a 
compressing of the stock, and certain portions of it will be broken. 
There will be very little of the pulverizing action, either of legitimate 
flour or of impurities. The flour stock will be incidentally pulverized 
and broken, and the impurities, which are usually of a tougher charac¬ 
ter than the better material, will not be appreciably disturbed. 

It is the tendency of all millers to want to pulverize or to make flour 
on most reductions, and especially the tailings and the lower grade rolls, 
and for this reason it may be expected that there will be a certain 
amount of differential at times in the reduction of this material. In 
fact, it can hardly be expected, nor is it desirable, that there should not 
be differential motion wherever smooth rolls are used. The disintegrat¬ 
ing action of this movement is so gentle when the rolls are not set closely 
together that it cannot but be desirable, though the amount of such 
differential may be varied according to the quality of material to be 
handled. With belt rolls it is a very simple matter to vary the move¬ 
ment, and it will be easy for any miller to demonstrate to his own sat¬ 
isfaction the proper motion to select in the reduction of various kinds 
of stock. There is a disposition among many who handle these rolls to 
set them very close, which is entirely wrong, principally because it 
does not accomplish the desired end. There is a lurking idea in the 
minds of many millers that the closer the rolls are set, the closer it is 
possible to set them and still keep the belt from slipping, the greater 
will be the amount of work done by such rolls. This is wrong. 

There is a proper point, there is a point in the setting of rolls which 
will accomplish more work than any other, and it is not the point where 
the greatest amount of power is consumed or where the rolls are set the 
tightest. It is where the stock is broken and not flattened. This is the 
greatest evil, the place where the greatest wrong is done to the stock in 
milling—this same close setting of the smooth rolls. It is a very simple 


GRADUAL REDUCTION MILLING. 


I I I 


matter to judge when the rolls are doing their proper work. The stock, 
as it comes fiom them, feels as though it had been ground and not 
mashed. Not only will the amount of flour made by the proper setting 
of the rolls be greater, and not only will the proportion of pulverized 
impurities be less, but the amount of power will be greatly less. A 
miller says to himself: “I have only a few pairs of smooth rolls. I have 
not enough; therefore I must set these rolls very tight, that I may hasten 
the operation of reduction.” He does not do anything of the kind; 
he cakes and hardens the stock; he makes it impossible to reduce 
this stock on anything short of a millstone. Having been treated by one 
set of rolls, those following have very little effect in hastening the work 
of reduction. 

The writer remembers to have heard a very forcible illustration of the 
reducing power of smooth rolls. It was by a Hungarian miller. He 
had been working in a mill where there were two pairs of smooth rolls, 
some three or four reels, four or five purifiers with adjustable sieves, and 
one or two pairs of millstones. All the work of the mill was done on 
this machinery. One or two reductions at a time were made on the 
rolls that were in the mill, they being adjusted for each class of material 
to be handled, while the middlings and bran were reduced in their proper 
order on the millstones. It was the habit of the head miller of this mill 
to reduce all of his middlings on stones, and the miller referred to said 
to him at one time: “Why do you not reduce your middlings on these 
smooth rolls?” Said the head miller: “We do reduce them as far as we 
can. We reduce them to dust middlings (fine middlings) on the smooth 
rolls, but we cannot reduce them farther by such means. ” The Hun¬ 
garian replied: “It is my watch to-night, and if I may, I will try,” and 
with the consent of his superior he did try. There was an accumula¬ 
tion of some ten barrels of this stock which had been produced by the 
breaking down of the larger middlings. He commenced to run it 
through the rolls, having it carried there by the help, and from the rolls 
to the reels. He reduced very carefully and very gently and got very 
nice flour. He had the middlings carried back to the rolls and passed 
through them again, with the same result—very nice flour. The third 
and fourth time was this repeated. Then he had about four barrels of 
stock remaining. After this the smooth rolls were almost entirely inop¬ 
erative. The stock kept going around and around without producing 
flour. He had been very careful; he had reduced the material very gently, 


112 


GRADUAL REDUCTION MI I,LI NO. 


only a little at a time, yet after four or five reductions on middlings which 
had passed through a No. 6 cloth, say, very little Hour could be made. 

This illustration meant a great deal. It showed or rather confirmed 
the belief that a complete corrugated and smooth roller mill is not quite 
the thing. It is hardly possible to completely reduce the product of 
the corrugated rolls with the smooth rolls. These rolls will go only so 
far, however carefully they may be handled, and no farther. There will 
be a certain amount of stock of most excellent character which is tail¬ 
ing over to the red-dog, and if the red-dog rolls be smooth iron, they 
will be tailing over the feed. In the case referred to by the Hungarian 
miller, he said that after he had reduced the stock five or six times or 
more, and found that little or nothing was being done on the last two or 
three reductions, he had it carried to the millstones and there reduced. 
As the material had been scalped repeatedly during the process of this 
reduction by smooth rolls, it was well purified, and was for this reason 
in good condition to be handled by the millstones. It made most ex¬ 
cellent flour, of a very high grade. After all, the use of the smooth 
rolls in this way was not without its beneficial results. Smooth rolls, 
properly used, are always purifiers. In behalf of the millstone idea for 
the purpose of reducing certain grades of stock in a roller mill, we may 
,call to mind the fact that more millstones are used by Hungarian mill¬ 
ers in proportion to the amount of flour made, than by the best Ameri- 
,can millers. Millstones are more necessary in aiding in the reducing of 
50ft than of hard wheat. 

The condition of things as here shown is what makes it so difficult to 
.carry out the full roller mill idea. After the stock has been submitted 
to a certain number of smooth roll operations, it is in a condition to 
effectively resist farther successful operations. It becomes hardened, 
.or, as previously expressed, calendered. There can be no doubt but 
that millstones or scratch rolls are necessary to carry out in an econom¬ 
ical manner, the desired purposes and results of gradual reduction 
milling. In the case of fine middlings, which are well purified and which 
have been made fine during a series of roller reductions, nothing better 
can be done with reference to the ultimate result, yield and all beino- 
.considered, than to make a reduction by millstones. After the stock 
has been hardened or flattened by smooth rolls, the reduction by mill¬ 
stones will again bring it into a condition where it may again be reduced 
.by smooth rolls, for which reason the stock may be farther purified in 


GRADUAL REDUCTION MILLING. I 13 

the handling by the gentler methods of reduction at a time when a dif¬ 
ferent purification is necessary. To illustrate: Say that we have pure 
middlings, or, to say the least, middlings as pure as we can get them, 
we then reduce them twice, perhaps, by the millstones, after which they 
are in a condition, even though they are somewhat hardened by pre¬ 
vious smooth roll reductions, to be again handled by smooth rolls. 
Furthermore, this material is in a condition, after leaving the millstones, 
to need farther purification. 


(8) 








CHAPTER XX. 


OVERGRINDING-THE PROPORTIONING OF THE VARIOUS PARTS OF A MILL- 

PRACTICE DEVELOPS A FORMULA—THE REDUCTION SURFACES OF A 

GRADUAL REDUCTION MILL. 

We all remember how much we used to read and talk about over- 
grinding, and'how we all agreed that from five to seven and eight bushels 
an hour was quite enough for a 4-foot buhr; and most millers practiced 
what they preached. The same subject in regard to feed of rolls has 
now come around to general discussion. To be sure, there is not the 
same danger from overheating that there is with buhrs, but there are 
many other evils attending overgrinding by the latter methods of re¬ 
duction, some of which are the same as from overgrinding on buhrs, and 
others which are distinct therefrom. 

Where the roll has too heavy a feed the yield of middlings from the 
wheat cannot be so large as under more favorable conditions. With a 
heavy feed the product of the roll takes more of the nature of a con¬ 
glomerate. The flour and middlings are forced into the particles of wheat 
rather than separated from them, as they would be with a lighter feed. 
In this way the separating machinery, or subsequent reduction machin¬ 
ery, cannot do its work so well as it should. The deleterious material 
from the wheat will be more intimately mixed with the desirable mid¬ 
dlings or flour portions. The former will be soft and flat. The bran 
will be lumpy and unevenly cleaned. There will be a part of it that is 
cut up as fine as sawdust, another that is clean, and the remainder which 
is rich and unfinished. Where there is this kind of bran—that is, un¬ 
evenly finished—it shows that that part of it which is overfinished—cut 
up—must have been cleaned or finished on a previous reduction, and 
the product of low grade material, which naturally belonged in the last 
reduction, went in with a higher grade of flour of. the other reductions. 
On the other hand, the lumpy and unfinished bran indicates that there 
were higher grades of stock taken from it at the last reduction or reduc¬ 
tions than naturally belonged there. All this may be the result of over¬ 
grinding, which means carrying too heavy a feed. 





GRADUAL REDUCTION MI LUNG. 


115 

The only way to make uniformly broad, clean bran is to have the 
grinding surface properly proportioned throughout, and not to feed any 
heavier than will bring about the best general results in the grinding. 

The evils of overgrinding apply to smooth roll reductions as well as 
to those by corrugated rolls. A writer has said: “If we have two 
rollers working together of the same diameter, and made of some hard 
material, they will seize and crush and squeeze the grain which is to 
pass through as soon as their distance apart is less than the diameter of 
the berry.” This, of course, would apply alike to any kind of stock— 
grain or particles of grain. When the stream of material going on the 
roll is so thick that one particle is driven into another, rather than 
touched by the roll, or when one side of a grain or granule is touched 
by the roll and the other side squeezed into a mass of similar material, 
the result cannot but be unsatisfactory. It makes a soft, spongy, pulpy 
mass. The different particles are mashed together rather than ground in 
such a way as to separate the various particles one from another. 
Where feed is heavy, as described above, so heavy that there are cer¬ 
tain particles which cannot be touched by the rolls, and where the 
attempt is made to reduce this material, the result cannot be called 
grinding or granulation, but rather mashing; or it might be spoken of as 
compression, and the pulverizing of the material would be merely inci¬ 
dental. There would be required an agitator, detacher, disintegrator, 
or other mixing machinery, to make it effective as a pulverizer. Such a 
reduction, followed by such means to effect a result, divests the rolls of 
all their purifying effects. The material might about as well be ground 
on a sharp millstone to begin with. 

Rolls are not intended solely for reduction machines, but they are 
used for their purifying effect as well, and when one takes the product 
of a roll reduction and runs it through some kind of an agitator, he di¬ 
vests this kind of a reduction of all its purifying and separating quali¬ 
ties, and degrades the whole combination to the level of a pulverizing 

machine. 

There can be no exact rule for the proper feed or capacity for roller 
machinery, but one may suggest an ideal principle which, though it may 
be unattainable in actual practice, makes a mark tor which to reach. If 
one were to say that the proper feed of a pair of rolls should be such 
that each granule of material will be touched alike on each side by each 
of the rolls, he would cover this ideal principle. It would imply a feed 



I 1 6 GRADUAL REDUCTION MILLING. 

of the thickness of the various single particles of the material to be fed, 
and not of any two of them. In exact and absolute practice this is 
an impossibility, but it is a good principle, and we can get as close to 
it as possible and thus be just that much nearer right than otherwise. 

If one were to sit down and make a formula or rule for the amount 
of stock to go on a roll, he could go at it in about this way: To com¬ 
mence with the wheat and take a 100-barrel mill as an example. As¬ 
suming that this was a winter wheat mill, and took four bushels and 
thirty pounds of wheat to make a barrel of Hour, this would make 450 
bushels of wheat ground in twenty-four hours, or eighteen and three- 
fourths bushels per hour. A 100-barrel mill generally has an 18-inch roll 
to begin with, and eighteen and three-fourths bushels per hour would 
be the feed of such a mill. If this three-fourths were not in the way, it 
would be easy to say that a bushel per hour per inch of grinding sur¬ 
face would be the proper feed for the first break. Therefore, in a mill 
which has four pairs of 9x18 rolls, there would be a feed of 384 barrels 
in twenty-four hours. 

To go farther with the breaks with the same purpose in view, it would 
be seen that the same amount of grinding surface was usually used for 
the second break as the first, and consequently the same grinding sur¬ 
face would be suggested for this reduction. Working with this in mind, 
we go on in the same way, to the third and fourth reductions. The 
third reduction should have one-third more grinding capacity than the 
first, which would give it twenty-four inches. The fourth should have 
two-thirds more than the first, which would be thirty inches grinding 
surface. In considering the fifth and sixth reductions it is easy to call 
to mind the fact that in many instances the same amount of grinding 
surface as on the first is more commonly used within the range of ex¬ 
perience than any other. But in the minority instances where more is 
used, the result of the grinding is better, and this result indicates that 
the fifth and sixth reductions should have the same amount of grinding 
capacity as the fourth. This would yield such material as would give it 
place with the highest grades of reduction stock. It is usually run there 
in any event, though not always deservingly so. Thirty inches of 
grinding surface for the sixth reduction advances that product beyond 
what it would be were there less, and at the same time it cleans the bran 
and leaves it broad. Where the grinding capacity is ample on the fifth 
and sixth reductions, the miller can go closer than where the feed is 



GRADUAL REDUCTION MILLING. 


117 


heavier, and without making soft middlings or red Hour in the case of 
the fifth break, or heavy, fine bran in the case of the sixth. 

Pursuing the same line of thought with the smooth rolls, in a 100- 
barrel mill, the following result would be found: The sizing of the mid¬ 
dlings would require the same amount of reduction surface as the first 
wheat reduction. The reduction of the first middlings would require 
two-thirds more, or thirty inches grinding surface; the second middlings 
the same as the first reduction of the wheat; the tailings should have 
9x18. Next comes the reduction of the dust middlings. This grade of 
stock is developed in the first break flour and the middlings separations. 
It will pass through a No. 8 or 9 cloth and over the 12 and 14 flour 
cloth. The first reduction of this stock would require one pair of 
9x18 rolls, as would also the second. Finally, the red-dog reduction 
would require the same amount of grinding surface as the first reduc¬ 
tion, and in addition a pair of millstones. 

We started out with a mill which would make a hundred barrels of 
flour in twenty-four hours. If a miller could make more money by 
making 125 barrels, it is not to be supposed that he would deny himself 
that privilege for the sake of maintaining some one’s theory or princi¬ 
ples. To recapitulate, on the basis of a 100-barrel mill we have the 
following: 


First reduction.18 

Second reduction.18 

Third reduction. 24 

Fourth reduction. 3 ° 

Fifth reduction. 3 ° 

Sixth reduction. 3 ° 

Sizing rolls.*8 

First middlings rolls. 3 ° 


Second middlings rolls. 

Tailings rolls. 

First dust middlings rolls... 
Second dust middlings rolls 
Red-dog rolls. 


inches grinding surface. 

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CHAPTER XXL 


4 


BOLTING-THE RELATION OF THE REDUCTIONS TO THE SEPARATIONS- 

THE RELATION OF THE CENTRIFUGAL REEL TO THE BOLTING SYSTEM- 

THE ACTION OF THE VARIOUS KINDS OF STOCK IN REELS-THE SPEED 

OF REELS. 

At the present time the relation between reduction and separation is 
closer, and there is less possibility of considering the two subjects sep¬ 
arately, than ever before. To speak broadly, the process of milling is 
a process of purification and separation. Everything tends toward such 
separation; it is the ultimate aim. Reduction machinery in itself is 
separating machinery; that is, looking at the subject from a single point 
of view it so appears. It shows that reduction is a detail of the sepa¬ 
rating scheme. Reduction machinery makes a separation, but not a 
division. After a reduction there is a conglomerate of pure stock and 
impurities, but there has been a separation; the impurities are liberated. 
There is no positive contact, one with the other, as far as the efficiency 
of that reduction goes, because it is only a reduction in so far as it lib¬ 
erates impurities. Where that work is not done it simply calls for an¬ 
other reduction. 

The positive separation of one grade of stock from another—flour 
from middlings, or impurities from either—can go no farther than did 
the reduction machinery immediately previous to its bolting or purifi¬ 
cation. Therefore if the positive separations are incomplete it is be¬ 
cause the separation by reduction machinery was incomplete. It is 
because of the impurities being improperly or incompletely liberated. 
Because of the intimate relation which the reduction, bolting and purifi¬ 
cation methods have one with the other, there is no way of considering 
them apart. Any change in one of these methods necessitates a change 
in the other, unless this change is made to bring about a more complete 
harmony between them. 

The more perfect milling operations become, the more intimate is 
this relation. There was a time in the history of milling when reduc¬ 
tion meant little more than pulverizing, and later it was reduction with 










II 9 


GRADUAL REDUCTION MILLING. 

incidental separating qualities. At that time the different processes 
were not so closely allied. 

However close the relation of the reduction machinery to s- parations, 
the distinction as to the terms reduction and separation must always be 
maintained in order to give clearness in discussing the general subject. 
Smooth rolls have been spoken of as purifying machinery, yet it would 
be confusing to speak of them as purifiers, however much they might 
aid in that operation. 

In speaking of smooth rolls as purifiers, it recalls the fact that the 
whole system of milling is a system of purification. Purification and 
separation are practically the same thing. There is no such thing as 
absolutely pure middlings, and the word is used in a licensed sense 
which is somewhat different from its real meaning. We try to purify 
low grade Hour on the reels and by the reduction machinery, but we do 
not do it. But as far as that goes, we do not absolutely purify mid¬ 
dlings. The difference is one of degree and not of fact ; altogether 
milling is a process of purification. Rolls, reels and purifiers are each, 
in the strict sense, purifiers and separators. All that this means is that 
there is a very intimate relation between the various processes of mill¬ 
ing, or rather between various details of a milling process. It may not 
be so with all alike, but in the minds of many the range of difference 
between the grinding floor and the separations above, is much greater 
than facts bear out. A reduction machine is a good one in so far as it 
reduces the stock and liberates the impurities at the same time. 

Most of the communications written by millers have more to say 
about millstones and rolls than any other subject. Since the introduc¬ 
tion of purifiers there has been as much improvement in the bolting as 
in any other of the milling methods. There has been as great an ad¬ 
vancement in the bolting separations as in the reductions or the pur¬ 
ifications as ordinarily considered. 

It is a popular thing to say that the introduction of the centrifugal 
reel marks the only radical improvement in bolting methods. 'The 
writer cannot see it in this way. To look at the bolting system as it 
was, say ten years ago, or even six, and know what it is now, it must be 
apparent to any one that bolting methods have gone through radical 
changes, and that these changes have contributed as largely to the gen¬ 
eral result as have the reduction or purification methods. Aside from 


1 20 


GRADUAL REDUCTION MILLING. 


the introduction of the centrifugal reels there have been no radical 
changes in bolting machinery. But this lack of mechanical change does 
not disturb the fact that with the same machinery and the same machine 
methods, but with different arrangements and more liberal ideas as to 
what was wanted, results as entirely different have been reached as 
could have been looked for Dy the use of distinct mechanical devices. 
As nearly perfect work is now done on reels as was originally done by 
the purifiers. The ideas and wants of the miller, as represented by his 
bolting arrangements, are entirely different from what they were a few 
years ago, and as the results are as much better as the methods are dif¬ 
ferent, this part of the mill cannot be said to be behind any other in the 
march of advancement. If one is still inclined to believe that the bolt¬ 
ing methods have not improved to the extent that is here claimed for 
them, let him consider what his mill would be with the old system of 
bolting; or, to express it better, if limited by the old ideas and accepted 
ends of bolting. The change in the system of bolting has certainly 
been as great as in the system of reduction, and there have been very 
great improvements in these separations since the successful introduc¬ 
tion of gradual reduction machinery. The idea of gradual reduction 
represents a much earlier period than the date of its successful intro¬ 
duction. It was the purification and bolting knowledge of-recent years 
which made the introduction of the gradual’ reduction system a possi¬ 
bility. The benefits of the improved reduction methods can never be 
realized unless the improved separating facilities are at hand. No re¬ 
duction system, however perfect, can atone for the deficiencies in the 
bolting methods. On the other hand, a good bolting system will take 
he work of ordinarily poor reductions and get fairly good results. The 
ntroduction of the centrifugal reel is merely an addition to bolting ma¬ 
chinery. It does not imply a change of system. It means the same 
thing to bolting machinery that any addition to roller machinery would 
mean as applied to reductions. The application of the centrifugal reel 
does not signify revolution in bolting. 

The original purpose in bolting operations was to separate the coarse 
from the fine material, and, to put it broadly, that is about all there is 
to it. But there are many arrangements which have made the details 
of such an operation various and complicated. In earlier years about 
all that was required of bolting apparatus was to make the separations 





12 1 


GRADUAL REDUCTION MILLING. 

of flour, middlings, shorts and bran, and this was quite frequently done 
on one reel. 1 here still remains a large number of mills which are 
equally as simple. It is no uncommon thing to see a mill with two 
reels, where the bran runs through them both, tailing off at the last, 
with the middlings as an intermediate product. This middlings separa¬ 
tion is made by putting a piece of coarse cloth on the tail of the last 
reel. The difference between such methods and those more largely in 

use is fully as great as the improvement in the machinery of other parts 
of the mill. 

1 he writer has taken occasion to notice the movement of the mate¬ 
rial in the reels, from the side and by taking off the tailboards at the 
ends of the reels. I here is quite a difference in the movements 

of various stocks in the reels run¬ 
ning at the same speed and of the 
same diameter, but containing 
material of different qualities. 
Take Fig. i as an example. This 
reel is supposed to be bolting 
break stock. Most of the mate¬ 
rial will fall between the rib A 
and the shaft B , a part of it fall¬ 
ing on the shaft, but most of it 
sliding off in the direction of A. 
This stock, it will be understood, 
is heavy and coarse. Referring 
to Fig. 2, which is bolting reduced stock, which originally passed through 
a No. 6 cloth, most of the material will fall on the side of the shaft be¬ 
tween B and C, probably more than one-half of it. The direction of 
the revolution of the reel in both instances is from left to right. It will 
be seen that the quality of the material with reference to its being coarse 
or soft has a good deal to do with its movements. 

The specific gravity of the material in a reel influences the quality of 
a separation; the heavier particles will go to the bottom next to the 
cloth and the lighter particles are inclined to float on the top. It can 
not be said that the movement of stock in a reel is inclined to favor 
such a condition of things to the same extent as with a sieve, but it is 
not possible to consider a movement which causes a constant rising and 
falling of material such as is usually contained in a reel where the 




I 22 


GRADUAL REDUCTION Mil,I.INC. 


heavier will not go to the bottom, and the lighter to the top, in a degree 
more or less positive, according to the disturbances in the reel. 

Referring again to the cuts, it occurs to the writer that the reel hand¬ 


ling stocks represented by Fig. 2 is running too fast to make the best 


separation. Another thing which has been noticed in the movement of 
the stock is that there is a larger proportion which falls over the shaft 
—that is, to the right of C, at the head of the reel—than at the tail. 
There are two reasons for this. In the first place, the stock is softer 


at the head than at the tail, and 
for that reason does not discharge 
from the ribs so readily. In the 
second place, the load is heavier. 
Better separations could be made 
when the reel did not run fast 
enough to throw the stuff over 
the shaft, or, rather, ran slow 
enough to keep it inside the shaft, 
or between A and J 3 , as shown 
in Fig. 1. In this case there 
would be less disturbances, less 



Fig. 2. 


mixing of the stock, and a better preservation of the natural condition 
of things according to its weight; that is, the lighter or fibrous material 
would tend to the top or away from the cloth, and the heavier to the 
bottom or next to it, and this makes a separation in a common reel 
more in accordance with the desired principles of the centrifugal. One 
might say that when the stock is thrown over the shaft by the rapid 
movement of the reel that the fall would be greater, and consequently 
there would be a better opportunity for a more decided separation ac¬ 
cording to its weight. The writer is inclined to believe that the severity 
of such an action, and the general disturbed condition of things in the 
reel brought about by this rapid movement, would more than counter¬ 
balance any benefits which it might be hoped to realize. 

Another thing which these observations prove is that what might be 
proper speed for a reel in one instance or with one grade of stock, 
would be an improper one in another and with another grade of stock. 
Thirty revolutions per minute is not too fast for the stock in Fig. 1, but 
it evidently is too fast for the reel as represented by Fig. 2. On the 
other hand, it is hardly to be supposed that the proper speed for the 




GRADUAL REDUCTION MILTING. 


123 


latter would be too slow for the former. All that this statement amounts 
to is to show that if a miller desires to reduce the speed of his reels, 
he need not go to the trouble or expense of changing them all, as he 
cannot hope to realize benefits in every instance. The common speed 
of reels, which is thirty-two revolutions per minute, is too fast for the 
best results on soft stock. When other more important things have 
been corrected, it will pay to look into this matter. 


CHAPTER XXII. 


THE NUMBERS OF CLOTH-THE RELATION OE CLOTH NUMBERS TO THE SIZE 

AND FEELING OF THE FLOUR—THE USE OF TAIL SCALPING CLOTHS- 

THE PREPARATION OF STOCK FOR BOLTING-THE REDUCTION OF THE 

PROPORTION OF SHARP MATERIAL A DESIRABLE FEATURE. 

It is not long since that millers were asking one another what num¬ 
bers of cloth they were bolting this, that, or another grade of stock on. 
These questions were approached delicately and cautiously; they were 
often intended to be shrewd. These questions were evaded; answered 
in indirect ways. This same thing prevails to some extent at the pres¬ 
ent time. The cloth numbers are no longer trade secrets, and for two 
reasons. In the first place, more is known about them; that is, the 
knowledge is more generally diffused among millers; and, in the second 
place—a more forceful reason—the matter of difference between the 
clothing of reels is not as serious or important in effect, when the differ¬ 
ence is at all reasonable, as some of our secretive neighbors would have 
us believe. Of course it is important to have these things right; but 
supposing that two millers are bolting certain grades of stock on a No. 
12 cloth, and say that these grades are uniform in each mill as regards 
their purity, it does not follow that the flour will be uniform in quality, 
either in color or granulation. Because flour is bolted on a No. 12 
cloth it does not indicate that all flour will be uniform, even though the 
stock out of which it is made—the stock as it goes into the reel—is 
uniformly pure. The granulation and the purity of flour are as much 
dependent upon the arrangement of cloths and reels, the disposition of 
the various stocks, as it is upon the numbers of the cloths used, within 
any reasonable bounds. Because in two different mills there are the 
same flour numbers working on the same flour stock, it cannot signify 
that the products will be uniform. 

Clothing a reel with a No. 10 cloth does not insure that that reel will 
produce sharp flour. On the other hand, clothing a reel with a No. 14 
cloth does not insure that that reel will produce clean or soft flour. Or, 
to go a little farther, either one of these reels may produce either sharp 






GRADUAL REDUCTION MILLING. 


I2 5 


or soft flour. The uniformity of the product of a reel is more often than 
otherwise dependent upon the uniform proportion of soft and sharp 
material going into the reel. If there is a larger proportion of sharp 
material, the flour will be larger grained and not so clear or clean as 
when that proportion is smaller. To illustrate this point is called to 
mind a method commonly in use under the buhr system. We will sup¬ 
pose the middlings were dusted over a No. 12 cloth. Now, these dust¬ 
ings were ordinarily flat, miserable looking and miserable feeling stock. 
On soft winter wheat they had a feathery texture and appearance. Take 
these same dustings which had gone through a No. 12 cloth, and put 
them in a separate reel clothed with a No. 12 cloth—the same number 
through which they had originally passed—and the product of flour 
will be nice and bright. This shows in an extreme degree the benefits 
to be realized by reducing the proportion of sharp material. Whereas, 
the No. 12 cloth, with the middlings in the stock, gave a product which 
was unsatisfactory, when these middlings were removed, the product of 
the same number was white, clear flour. This means that the propor¬ 
tion of sharp material in that reel was reduced on the stock made softer, 
and therefore the product improved. 

The cut illustrates this same thing, carried out in another way. It 
will be supposed that the stock going into reel is a floury one, and at 
the same time contains middlings as coarse as those which will pass 
through an o cloth, and from that on down in fineness to flour. But the 

larger proportion of it is flour 
stock. Let it be supposed, for 
example, that these reels are bolt- 



grades mentioned from the four 
middle breaks. It will be noticed 
that each reel is clothed with a 
No. 12 cloth at the head and that 
there are scalpers at the tails of 
the two first reels. Now, as men¬ 
tioned before, the stock going 
into the first reel contains mid¬ 
dlings as coarse as will pass 


through an o cloth, and from that on down finer, but with a good pro¬ 
portion of Hour. For the latter reason the Hour from a certain part of 





































126 


GRADUAL REDUCTION MILLING. 

the first reel will be all right and satisfactory. But as the proportion of 
sharp material increases, because of the flour being taken out on the 
first 12 cloth, it becomes necessary to reduce this proportion of soft 
stock, which is done by placing the No. 5 at the tail. Perhaps it would 
be better if there were more of this latter cloth. The tail of the No. 5 
would go to the grader or purifiers, together with that proportion of the 
product of the No. 5 next to the tail which was sufficiently free from 
flour. Now, by removing these middlings which will pass over the 5, 
or that portion which is taken off which goes through the 5, the propor¬ 
tion of sharp stock is reduced, and is again soft enough to be bolted on 
a 12. The same operation is gone through again ; flour is taken through 
this 12 cloth on the second reel, and the proportion of middlings is 
again on the increase, and it is necessary to take off more middlings so 
as to make the stock soft enough to be floured on the next reel. This 
is done by putting the 10 cloth on the tail of the second reel. The 
middlings which pass through the 5 pass over the 10, and the desired 
object of reducing the proportion of soft stock is accomplished; that is, 
sve have the cut-off from the 12 and the product of the 10 to go to the 
third reel, which is soft enough to bolt clean on the 12 cloth of the third 
reel. 

This will work out in actual practice. It is only necessary to keep 
down the proportion of sharp material in order to make clean flour 
through a 12 cloth, or at least as clean as it would be from such stock 
on a finer cloth were the conditions less favorable. Say that the 12 
cloth of the second reel did not bolt the flour as clean or as white as 
desired, that would indicate that there was too much sharp material com¬ 
ing through the 5 cloth, which might be sent off with the tail, which 
could be done by closing the slides under the tail conveyor. With a 
light load on the reel this would work out in the same way in the rela¬ 
tions of the second to the third reel. 

The experience of millers who have tried these arrangements will 
justify the correctness of the principle, and great benefits can be realized 
in mills where this principle is not in use. 

The above gives prominence to the expression 12 cloth, but this num¬ 
ber is used merely as an illustration. 


CHAPTER XXIII. 


ARRANGEMENT OF BOLTING DEVICES—THE PROPER CONDITION OF STOCK 

TO BOLT PROPERLY-THE SCALPING OF MIDDLINGS BEFORE SEPARATING 

FLOUR-PROPER AND IMPROPER METHODS COMPARED—THE VALUE OF 

PROPER SCALPING ARRANGEMENTS. 

In the last chapter something was said about the relation which the 
proportion of sharp material in a reel bore to the product of that reel, 
and an illustration was used to show the effect of decreasing the amount 
of sharp material in the reel at the same time that the flour was taken 
out. This was done by placing scalping cloths at the tail of each reel 
which gradually increased in fineness, counting from the first reel down¬ 
ward. Thus the stock became finer as it passed from reel to reel. There 
are other means of accomplishing this result, which will be mentioned 
in the course of this chapter. 

The whole object of this is to keep the material going into the various 
reels in a condition so that it will contain the proper proportion of soft 
material to bolt clean, and at the same time a sufficient amount of sharp 
material to give the reel its required capacity. One great point with 
the centrifugal reel is that it will bolt softer stock than a common reel. 
It will re-bolt flour which would paste a common reel so that little or 
nothing would come through. 

This principle of keeping the stock as soft as possible to bolt is one 
in which the writer has great confidence. By such an arrangement it is 
possible to keep thoroughly dusted stocks going on the rolls or purifiers, 
which facilitates the work of feeding and purification, and gives the 
rolls and purifiers less to do and a better chance to do their work, and 
to do it well; therefore a less number of reductions of the middlings 
and other stocks is necessary in order to finish. It is quite often the 
case that floury material is run on the rolls to be reduced, when such a re¬ 
duction is not necessary. By merely removing some middlings or sharp 
material, which there is in this stock, it can be bolted and will produce 
white, clean flour. Then by taking the middlings which are separated 
from this stock, they can be reduced and thus accomplish in a direct 


12 $ 


GRADUAL REDUCTION MILLING. 


and simple way, and at a single reduction, what it would have taken 
many to accomplish were the floury stock and other material run to the 
rolls together. 


Calling to mind other methods of the application of this principle, 
stock from the sizing rolls will be taken. One way of arranging and 
clothing for such separation is here shown. 

Here the stock from the rolls is going on a No. 12 cloth and before 
any of the middlings are taken out, Hour is taken from the stock. What 
goes through the cloth goes into the next reel, which, to compensate for 


x iL_ 12 

0 

the probable result with a coarser 
cloth, is clothed with a No. 14, for 

r:,CUR tail /NFS the flour portion, and No. 7 through 

- c777 y 

which to take the fine middlings for 
the middlings bin. The stock which 
goes over the No. 7 ordinarily goes 
to a purifier. The details of such 
fr an arrangement, though not un- 

common, are altogether objection- 


lb 4 

7 

FL OUR purjf / 

-— K-<;->»—>~ 

- < -^- 


Fig. 1. able. It is suggested that the ar- 



4 - 




t-a!\L//VCS 
»— ! - 




->- 


PURIFIER 


rangement shown in Fig. 2 be substituted. 

Here the product of the sizing rolls goes on a No. 7 cloth first, where 
the flour and fine middlings are taken out. 'Then the material goes 
through the o, is in a dusted con¬ 
dition, and can go directly to the 
purifiers. The stock which goes 
through the No. 7 is soft enough 
to bolt clean and bright through 
the No. 12 cloth on the next reel. 

The tail of this reel is No. 6, 
which will carry over some stock 
that originally went on the No. 

7. This is on account of its be¬ 
ing softer in this reel—that is, 
containing a smaller proportion 
of sharp material—than on the reel above where it went through the 
No. 7 cloth, and had the coarse middlings to make it bolt freely. 

The product of the 6 cloth will be much cleaner and brighter than 
that of the 7 on the tail of the reel in the other instance, because it 



FLOUR 


<— 

-W—7- 


PURIFIER 


O, 

< 5 > 


Fig. 2. 






































GRADUAL REDUCTION MILLING. 


129 


does not have the heavy, coarse middlings out of which the flour has 
been taken, and which will wear off or beat their impurities through the 
cloth. It is very clear that this arrangement shows benefit to the flour, 
as well as the middlings. In the first place, the middlings are dusted 
over a No. 7 cloth, which takes out all the flour and fine middlings; and 
secondly, the flour and middlings in the second reel are benefited by 
not being associated with the heavy and sharp stock above. 

It is not long since the arrangement (or its equivalent) shown in Fig. 
3, was used in separating the middlings and flour of the four middle 
breaks. 

Such an arrangement has the same objections as the one shown in 

Fig. 1 in the handling of sizing 
stock. In the diagram here given 
there is flour, together with all 
grades of middlings as coarse as 
000, going into the first reel, and 
flour is taken off on the first one 
through a No. 11 cloth. It might 
be a 12 or 13, and the evil of 
such an arrangement would be as 
great. In any event, coarse mid¬ 
dlings go off over a 2 cloth, and 
the product of this cloth, together with the No. it, would go into the 
bottom reel, and it would still be too sharp to bolt clean on the numbers 
given, unless a larger portion of the product of the No. n went into 
this reel, in which event the stock 
would be too soft to dust the mid¬ 
dlings which passed over the 9 
cloth. Thus it will be seen that 
in one instance the flour will be 
sure to contain more impurities 
than it would under more favor¬ 
able circumstances, and in the 
other the stock would be too soft 
to dust the middlings over the 
No. 9 cloth. This illustration is 
given because it is one which is known to have been used in a number 

of instances, with the result described. 

(9) 



—K-< 


M/DS 


Rig- 3- 



COARSE Ml DS 



—<-->» *■— 



-- 777 - 

FINE Ml DS 


" 12 

13 


FL 

0 UR 

- i - 


DUST 


- 

Fig- 4. 












































1 3 ° 


GRADUAL REDUCTION MILLING. 

Having had experience with the arrangement illustrated in Fig. 3, the 
one given in Fig. 4 is what suggested itself as a remedy. 

Here the middlings are scalped and graded first and the Hour taken 
out afterward. The hour and dust middlings are taken out through No. 
9 cloth and the coarse and fine middlings graded over a No. 3, or any 
other desirable number. This brings the stock going into the second 
reel soft enough to bolt clean and still sharp enough to bolt freely, it 
having originally passed through a No. 9 cloth. This arrangement not 
only brings this stock soft enough to bolt clean, but is also sharp enough 
in the first reel, having all the large middlings with it, to thoroughly dust 
all grades of middlings over a No. 9 cloth, and before it gets to the 
grading number. This is quite desirable and saves a dusting reel, which 
would be necessary on soft wheat according to the first arrangement. 
It takes advantage of the large middlings to aid in dusting, and at the 
same time gives the stock to the second reel soft enough to bolt clean. 

The clothing of the upper reel is a good deal a matter of judgment. 
In a low grinding buhr mill a No. 9 cloth would be too fine, or, in fact, 
in any mill where the grinding is done on buhrs. These illustrations 
show the principle and details of arrangements to reduce the proportion 
of sharp stock before taking off Hour, and attempt to show the benefits 
to be derived therefrom. 




CHAPTER XXIV. 


THE MEANS OF MILLING PROGRESS-THE EFFORT TO BE CLOSE AND SECRET 

-A LARGE NUMBER OF FIRST-CLASS MILLS DESIRABLE-THE EFFECT OF 

AN INTERCHANGE OF IDEAS-THE EXPERIENCE WHICH DEVELOPS INVENT¬ 
IVE MILLERS-ORGANIZATION IN MILLING MATTERS-THE LACK OF 

UNANIMITY IN MILLING OPERATIONS—REDUCTION BY CORRUGATED 

ROLLS BETTER UNDERSTOOD THAN SEPARATIONS-THE SAME NAMES DO 

NOT ALWAYS INDICATE THE SAME STOCK-THE DEVELOPMENT AMONG 

MILLERS. 

What advancement there has been in milling, and whatever advance¬ 
ment there is to be, has and will come from a united experience and an 
interchange of ideas. The mill that has come the nearest running with 
closed doors is not the one which has done the best work, made the 
most money, or contained the best help. One man, or a dozen, will not, 
cannot work out the milling problems of the future any more than did 
the same number in the past. In the winter wheat region, where there 
is the poorest woik done, there is the greatest show of closeness, as to 
the equipment of the mill and those engaged in running it. In the best 
mills of the Northwest there is more freedom, less show of secrecy 
than in the little mills. If in Minneapolis there had been, dur¬ 
ing the past milling years of that city, only one or two first-class 
mills, it cannot be said that even this number would have enjoyed the 
prosperity which they have enjoyed in the company of a large num¬ 
ber of equally well-equipped, ambitious and successful neighbors. It is 
the aggregate of the mills, as well as their splendid work, which has 
helped to make the money for the individuals. It has given Minneapo¬ 
lis a reputation which has attracted buyers from all accessible markets. 
This is because of its reputation for making a large amount of first-class 
flour, which reputation it would not have enjoyed to its present and 
past extent, with a small number of mills. A colony of well-equipped 
mills, in a town of Indiana or Illinois, would benefit the individuals of 
that colony in the same way. A State which has only a small number 
of mills is not the best State in which to build a new one; but rather a 


1 3 2 


GRADUAL REDUCTION MILLING. 

region which has a large number of first-class mills and, consequently, 
one which has the reputation of furnishing good flour. There is at least 
one city in the winter wheat region which was formerly a large milling 
center, and was so prominently known as a point where good milling 
was done, that nearly all the mills of the neighboring States regarded it 
as being to their advantage to brand their flour as being made in that 
city. It is to the advantage of good millers to have other good millers 
around them, in that it enhances the reputation of the flour product of 
that locality. Furthermore, such a course attaches additional value to 
the price of every piece of productive land in that locality, and, in that 
way, adds to the wealth of the whole community—which means each 
individual in it. One can best have wealth where there is wealth to 
draw from. Thus it will be seen that to be isolated in the possession of 
milling knowledge is not a desirable state of affairs, where one wishes 
to meet the markets of the world. 

The effort to be close and secret with milling information is the spirit 
which, in its completeness, would keep all in one low condition. It is 
the spirit which would have made all invention impossible. If it were 
possible for men to refrain from uniting their ideas, from talking about 
their work, such a thing as human progress would not be known. The 
united ideas of many men made the steam engine. Watt did this work 
for those who went before him. He put their ideas in tangible shape, 
and those who followed him have been adding a little all the time until 
we have the better machine of to-day, which no man can call his own. 
There never was, and never can be, a man who can break short off from 
the train of thought of other men and do something, invent something 
which is distinct and apart from the ideas of his friends and ancestors. 
He who has the credit of being a great inventor is simply a great ac¬ 
cumulator—one who has that quality of mind which takes up what others 
have been thinking of in a way more or less misty, and brings all to a 
climax in a useful machine, or other combination of thought. He is a 
climax; the others preparatory. This shows what progress means, and 
how it is brought about in milling as well as in anything else. 

The most successful millers are not those whom the world would call 
original or inventive men. They are quiet, level-headed, inquisitive 
people, who know a good thing when they see it, and whose only idea 
of success is in the ultimate result. They don’t care whether an idea is 
their own or that of somebody else, so that it does the work. They 





GRADUAL REDUCTION MILLING. 


*33 


know how to profit by their own mistakes and other peoples’ successes. 
They are organizers and systematizes of what they believe to be right 
in nulling. Narrow personal vanity does not embarrass their move¬ 
ments. It is true that the experiments and changes, which have been 
necessary during times past, have caused a great many millers to be 
restive and inclined to tinker with and alter what might be profitably 
let alone. 

I here is no unanimity of ideas as to what are the true principles con¬ 
nected with gradual reduction milling. All seem to be united in regard 
to the reductions themselves. All seem to believe in the utility of 
gradual reduction by rolls. Millers are unanimously of the opinion that 
they ought not to have less than six reductions, if they have the money 
to pay for them, and again they seem to approximately agree as to 
the corrugations which shall be used on each break. Of course there 
is the occasional crank who indulges in wide departures from accepted 
methods for departure’s sake. There are those who desire to be unusual, 
who get a lame sort of satisfaction by standing alone even though there 
be no rhyme or reason in their departure. A man who uses twenty 
corrugations on the first break cannot do that thing rationally. Reason 
would lead him to see that the fine corrugations are calculated to cut 
the bran, as it is on the original wheat berry, into small pieces. If rea¬ 
son does not show this thing, the results certainly do. With fine corru¬ 
gations on the first break, the third and fourth breaks would show a fine, 
stringy mass, being distinguishable from the stock usually going to such 
.reductions by every evil and deranging equality which can be imagined 
at this stage of the process. The writer asked a man who was doing 
just this thing why he did it, and he answered, “because he thought it 
did better work. ” He was asked if he were sure of it, and he said he was. 
He voluntarily went on to say that he had never heard of such an arrange¬ 
ment before, and that it was an original idea with him. He had another 
original idea, as he claimed, which was to pass all his middlings through 
smooth rolls immediately after passing them over a middlings scalper, 
after which he scalped or dusted them again before purifying them. The 
point which he saw here was, as he explained it, that he did not have to 
take care of so many large middlings; that they were more uniform in 
size. While it is desirable, but not possible, to have middlings of an 
approximately uniform size before purification, the evils attending the 


i 34 


GRADUAL REDUCTION Mil.LING. 

means of reaching such an end are so monstrous as to render such an 
idea entirely unworthy and unreasonable. 

It has been said that there was a certain amount of unanimity as to- 
the reductions, and an illustration of a very startling exception was 
given. The original statement is qualified by including particularly the 
use of corrugated rolls, there being more harmony as to how to use 
these rolls in the reduction of wheat than in the use of any other ma¬ 
chines. When it comes to separations, there are apparently as many 
different ideas as there are mills. Every miller has his own peculiar 
ideas as to separations, and exhibits as well what might be called a cer¬ 
tain amount of individuality in the use of smooth rolls and in the classi¬ 
fication of stock which goes thereto. One reason why there is this great 
diversity of methods and so-called systems, is because it so often hap¬ 
pens that the miller knows only his own way, and as no two men are 
alike in their way, when there is no concert of action, the general 

methods must be widelv different. As we become more and better ac- 

* 

quainted with one another’s ways we will more nearly approach a com¬ 
mon system, and at the same time that we do this, we will do better 
work. The way in which the change in our milling system has been 
worked out has been very wasteful, both as to energy and money. There 
have been too many single-handed struggles. Millers working next door 
to one another have been alone in their work. Where one man tries to 
do all himself, and by and for himself, he is taking a larger contract than 
was ever accomplished by one man. In the end he must accomplish 
his work by help from others. The best milling system which we are to 
have will be that which is made up of a united experience. It will be 
the system in use in nearly all the mills in the country. There will be 
few variations as to details. When this time comes we will speak of a 
milling system with a common understanding as to what is meant. Our 
discussions will be on very narrow points, something like those indulged 
in by the employes of cotton and woolen mills. These bring harmony 
as to all the general principles—only the fine or small points being left 
for general discussion. 

It is hardly necessary to illustrate what is meant by the great differ¬ 
ence in the management of mills, in the classification of material and in 
the use of rolls, reels and purifiers. We have only to glance around 
us, or maybe to look at the history of our own performances. We may 


GRADUAL REDUCTION MILLING. 


*35 


take the tailings of one mill and compare them with the same stock in 
name in another and find the appearance entirely dissimilar, so much so 
as to indicate that all previous separations must have been different. 
We find the Hour from the tailings in one mill white and bright looking. 
We find the tail from the tailings reel white and flaky and going anywhere 
that will give it a good shaking up and keep it from passing into the feed. 
In the other mill we find the tailings flour dingy and the tail of the reel 
poor and thin and spouted directly to the bran duster. We find these 
same differences all through the mill. We find them in the cleaned 
wheat, in the break flour, in the middlings, in the patent flour, and in the 
low grade flour and feed; and we find the same difference in the prices 
received for these products. There are no products in flour mills which 
will compare in uniformity with the standard sheeting of cotton mills 
which is made in the same way and at the same cost by nearly every 
cotton mill in New England. As the mechanical system approaches 
uniformity the system of handling or managing will, in that same degree, 
become more exact and uniform. 

There is a system in the operation of cotton mills which, with modifi¬ 
cation, can be applied to the operation of flour mills, and which, in its 
completeness and efficiency, is far ahead of anything of which most of 
us have knowledge. In speaking of system in this sense, it is to sepa¬ 
rate distinctly and clearly the thought as to process and system in a 
mechanical sense. Particularly is meant the business system and the 
organization of the help, in the operation of the machinery. It is safe 
to say that the entire profits of cotton milling, in years past, have been 
derived from the little things which are totally neglected in nine-tenths 
of all the flour mills. In the cotton mills they figure and calculate to 
a nicety and exactness which would be astonishing to those not familiar 
with their methods. The most wonderful thing in these calculations, 
which trust to such narrow and almost imperceptible points for margins, 
is that they are realized. 

The longer people think, talk and argue about a given subject, the 
less there is to talk about. All arrive virtually at the same conclusion. 
All difference of opinion is settled by reason and experience. Facts 
eventually override all prejudice. There may be three classes of opin¬ 
ions as to matters pertaining to our daily living. There are the opinions 
born in us—opinions for which we will fight. Then there are those we 
have fallen into accidentally, hardly knowing how, which we hold to less 


* 3 6 


GRADUAL REDUCTION MI I.LING. 


tenaciously than the former; and, finally, there are the opinions at which 
we arrive through a process of reasoning, which latter class we can talk 
and argue about without getting disturbed or excited. These are opin¬ 
ions which are readily changed in the same way in which they originated. 

The older processes of milling were not calculated of themselves to 
make thinkers of the men who ran the mills. The disposition was to 
do as had been done before and without other basis for so doing. There 
is nothing in the present processes which has not been developed by 
thought and reason. The millers who operate the mills of the present 
time are generally thinkers, because the results in such mills have been 
developed by the thoughtfulness of the people of the present times. 
The millers of this time and generation are less mechanical in their na¬ 
ture or disposition than will be the millers of the next decade, providing 
no serious changes be made in the processes of the present time. It is, 
and has been, the work of the millers of this generation to revolutionize 
the processes of milling. It will be the work of the next generation to 
run these mills, and in time they will develop into the same machine 
condition as the millers of the earlier times of which we speak. It will 
not be a question of processes or methods, but simply the doing with 
machines that which is set before them to do. There will be none of 
the inventive or logical qualities required of the operative miller. 

The same experience which has developed the inventive and logical 
qualities in millers, such qualities being necessary to work out the de¬ 
tails of gradual reduction milling, will make it difficult for them to settle 
down to the mere running and operating of the mills. It is the same 
inventive spirit which has been so brought about and developed which 
is liable to overreach itself. For this reason we will continue to have 
trials and experiments in particular details of milling when trials and ex. 
periments are no longer necessary. There will be, as there already have 
been, machines put on the market for which there is no particular use. 
This is justified to a certain extent by the millers expecting and demand¬ 
ing something new. This develops a disposition to hunt someth’ng for 
a machine to do rather than to seek for something which will do a cer¬ 
tain thing. But all this is preparatory to the formulation of milling 
ideas and their eventual incorporation into a complete milling system— 
a system winch is the result of the reasonings and experiences of times 
past. At that time there will be no great difference as to the methods 
pursued in the different mills. The milling results will be due more 


GRADUAL REDUCTION MILLING. 


137 


largely to the operation of the mills, as to their difference from other 
mills, than to differences of system. Take the present time, for in¬ 
stance; there are many mills which are doing superior work because of 
superior methods of reduction and separation, but the difference is not 
nearly so great as it once was. The margin as to the quality of the 
goods between different mills is gradually narrowing. It will become 
closer and closer until the margin is less marked and the only difference 
to be distinguished is owing to the lack of fulfillment of the milling idea 
as understood, or, perhaps, the quality of skill and ability displayed in 
-the operation of the mill. 






































































































A JOURNEY THROUGH THE MILL 







CHAPTER XXV. 


THE CLEANING OF WHEAT-PURPOSE OF WHEAT PURIFICATION PRE¬ 
VIOUS TO REDUCTION-RELATIVE IMPORTANCE OF WHEAT CLEAN¬ 

ING TO VARIOUS GRADES OF FLOUR—DEVELOPMENT OF CARELESS 

METHODS-OVERWORKED CLEANING MACHINERY-DISPLACEMENT OF 

CLEANING MACHINERY-GRADUAL CLEANING A PART OF THE GEN¬ 
ERAL MILLING PROCESS-REDUCTION OF THE YIELD BY GRADUAL CLEAN¬ 
ING-REDUCTION IN THE PERCENTAGE OF LOW GRADE FLOUR BY MORE 

PERFECT WHEAT CLEANING-AMERICAN AND HUNGARIAN WHEAT CLEAN¬ 
ING METHODS COMPARED-GRADES. 

With this chapter we begin what may be called a journey through the 
mill. We will first take up the wheat as it enters the mill, and follow 
it through the cleaning apparatus and the reduction and separating op¬ 
erations, considering at each stage of the process the milling qualities 
and peculiarities and method of handling the various machines, and the 
principles involved in their operation. 

The cleaning of wheat and the purification of middlings have in 
mind the same result. This statement might be turned around and 
read “the purification of wheat and the cleaning of middlings.” Cus¬ 
tom and precedent are in favor of the first expression. Milling the 
wheat, properly speaking, may be said to begin with its reduction, its 
handling by the cleaning machinery being the preparation for the purifi¬ 
cation process. And it is clear to see that any impurities taken out 
previous to reduction, renders the work of the separations infinitely 
easier than it could possibly be were this process deferred until after the 
reduction of the wheat. The purification of the wheat after it is re¬ 
duced cannot but be an incomplete process. Only such particles as are 
of sufficient size, and detached from the outer coverings of the grain, 
can be pure or in a condition to be purified. The finer particles, or 
flour, are more or less intimately mixed with the portions deleterious to 
its bread making qualities. Therefore, any impurities taken out of the 
wheat previous to its reduction means more as applied to the final re¬ 
sult than can any of the methods of purification which follow. The 


142 


GRADUAL REDUCTION MILLING. 


taking out of the impurities at the tail end of the mill always had an 
unnatural look to the writer. It always appeared that there would some 
time be a method which would not allow the impurities to come out 
after the better portion had been removed. This would mean a 
separation of the impurities from the flour, and not the separation of 
the flour from the impurities. It seems that the wallowing of a lot ol 
material through a reel wherein the impurities were retained until the 
last is an unnatural process, and one which in time will be supplanted. 
By such a way—that is, the common way—the purity of the flour is 
dependent upon the proportional purity of the entire stock or conglom¬ 
erate as it enters the reel, and not upon the quality of the distinct flour 
particles. By this is meant that there may be a small proportion of 
never so high a grade of flour mixed with a larger portion of impuri¬ 
ties or inferior flour. The quality of the flour that comes from the reel 
which bolts this stock is influenced only by the proportion of impurities, 
and not by the quality of flour stock which may be mixed therewith. 
The only effect which this high grade stock has, is in reducing the pro¬ 
portion of deleterious material. It is well known that the lower grades 
of flour contain a proportion of the best stock in the wheat, together 
with a certain other proportion of the worst and poorest stock. As the 
quality of flour is rated by its weakest points, the result is apparent. 
Such a result is brought about by a method of milling which carries by 
far the largest portion of impurities through the mill, in the meanwhile 
taking out and grading the desirable portions. On the face of the mat¬ 
ter this looks unsatisfactory, and the suggestion would be to remove, in 
so far as it is possible, the impurities in and of the wheat previous to its 
milling. But in the light of the present milling information, nothing of 
that kind is at hand, nor have experience or experiments proved any¬ 
thing worth)' in this direction. But it does look unreasonable that we 
take out the impurities at the tail end of the mill, or during the various 
detailed processes, and after the flour and middlings have been removed. 
All this goes to show the importance of wheat cleaning or wheat purifi¬ 
cation. It shows that the nearer we come to purification in the begin¬ 
ning, the more we can add to the value of a bushel of wheat in milling. 
It shows, further, that the nearer we can come to purification at the head 
of the mill, in the same proportion will the value of the products be 
enhanced. In the present instance this calls our attention directly to 
wheat cleaning methods. 


GRADUAL REDUCTION MILLING. 


J 4 3 


The cleaning of wheat is more important to the break flour than to 
the middlings. Imperfect wheat cleaning shows more plainly in the 
clear flour than in the patent. The flour which is made in the effort to 
reduce the wheat to middlings is contaminated—is rendered impure in 
proportion as the wheat is improperly or imperfectly cleaned. The 
particles of impurities which are of the same size as the flour particles 
cannot be removed. The scouring of the wheat makes a separation 
which is prolific in its benefits to the break flour. The natural dust of 
the wheat must, of necessity, go into this grade of flour if it be not re¬ 
moved by the cleaning machinery. Wheat cleaning is neglected in 
American mills. Our wheat cleaning machinery is in good condition. 
We do not lack in its quality, but we do not use enough of it. We 
rush a lot of wheat through a separator, through a scourer, into a brush 
machine and then to the break bins. We put it through the motions. 
It is a habit with us to do this thing, and, in common with many other 
habits, there is a certain degree of carelessness about it. There is no 
denying that there is a great deal of carelessness in wheat cleaning. It 
occurs to me that if the miller were to sit down and think that what¬ 
ever impurities are left in the wheat will go into his break flour and re¬ 
duce its value in the market so many cents per barrel, he would reform 
his ideas, or lack of ideas, in regard to this wheat cleaning matter. 

One great reason for the carelessness of wheat cleaning methods lies 
in the fact that about all there is left of the older methods of milling is 
that of wheat cleaning. The attention of millers is particularly attracted 
to new machines and new methods, and in their development it is not to 
be wondered at that something which was old, something which did not 
participate in the change, should be regarded with a certain degree of 
indifference. There are millers to whom this talk does not apply, how¬ 
ever. 

As to methods of wheat cleaning, the subject is one which can 
not be treated with any degree of freshness. The method of wheat 
cleaning—that is, the course of the wheat, the operations to which it is 
subjected—is better understood than any other of the milling processes. 
The faults in wheat cleaning are not faults of ignorance; they are more 
faults of carelessness and thoughtlessness, a course which leads millers 
to double the capacity of the mill, oftentimes, without making corre¬ 
sponding changes or alterations in their wheat cleaning machinery. One 
thing which may be done is for the miller to examine his machines, then 


144 


GRADUAL REDUCTION MILLING. 

numbers, in order to determine their size, and then refer to the cata¬ 
logue of the maker and see if their capacity is what it should be. This 
thing often happens: the machine is large enough if run twenty-four 
hours; if run twelve it is obviously too small. A machine never should 
run to its maximum capacity. If it could do good work when so oper¬ 
ated, it would naturally be supposed that it would do so only under ideal 
conditions. Competition among the makers of wheat cleaning ma¬ 
chinery naturally tends to cause them to exaggerate the capacity of 
their machines. One which is advertised to handle from forty to sixty- 
five bushels an hour will naturally do better at forty than on any other 
feed. The number of the operations should always be considered. If 
a machine is arranged to take out the heavier and coarser impurities, it 
is natural to suppose that it will not operate with equal facility and suc¬ 
cess upon the finer, smaller, lighter and more dangerous impurities. 
The warehouse separator removes the coarser and larger material, to¬ 
gether with the larger volume of dust. There remains other foreign 
material to be taken out in the course of subsequent operations, and 
which can best be done by machines which are constructed for the pur¬ 
pose of recognizing finer and more delicate differences, which become 
necessary in the cleaning of the wheat. It has often been noticed that 
when a feed on a machine was too heavy—much more than could be 
handled effectively—the miller would buy another machine of the 
same size and pass the same stream through it, hoping thus to remedy 
the evil. But it cannot be done in that way. It is hardly within the 
range of possibilities to expect any number of overworked machines to 
accomplish a desired result. Taking the case cited, benefits would be 
realized only by dividing the stream, sending half of it to one machine 
and half to another. This same principle applies to the operation of 
any machine in the mill. For instance, a brush machine may have 
twice as much to do as it ought to have; that is, a stream twice as large 
as should naturally and properly be expected, is made to pass through it. 
And, by the way, this is not an unusual condition of things; and, at the 
same time, it is not unusual to see two such machines working on the 
same large volume of stock. There is a brush machine made which 
absolutely rebels against excessive overwork. It carries over whole 
w r heat into the screenings pile. 

A great many wheat cleaning machines are overworked, not because 
they are too small for the size of the mill, but because they are run at 



i45 


GRADUAL REDUCTION MILLING. 

too heavy a feed at various intervals during the running of the mill. 
r I o explain: The miller puts on a heavy feed, runs his cleaning machin¬ 
ery for an hour or so, accumulates a stock of wheat in the hoppers, and 
then throws out this part of the mill until the supply is nearly exhaust¬ 
ed, when the operation is repeated. Instead of putting on a light feed, 
and one at which the machine would do the best work, and running it 
a greater number of hours, he hastens the work, through force of habit 
in some instances, and, the more discreditable motive in others, the de¬ 
sire to have a smaller amount of machinery to watch than the necessi¬ 
ties of the case would demand. There is quite as much necessity for 
wheat cleaning machinery to run all of the time as there is for a mill¬ 
stone or a buhr. If it is desired that it should only run part of the 
time, its capacity should be estimated accordingly, and it should not be 
forced to do unnatural and incomplete work. When the wheat is poured 
on to a separator, say, in a large volume, the suction on the wheat, as 
it enters the machine, cannot be uniformly distributed thioughout the 
grain, and for that reason cannot take out a uniform quality of light, 
poor stock. At the same time there will be a certain proportion of 
the light stock removed, and a certain other proportion of rich 
stock or whole wheat taken out, while the wheat which is supposed to 
have been cleaned will contain light impurities which should have been 
removed. Here the miller finds himself between two fires—rich offal or 
screenings on the one hand, and poorly cleaned wheat on the other. 
The rich screenings are brought about in the same way as the other rich 
offal—by the heaviness of the feed—the screens being overloaded and 
thus forced to tail over in a wasteful manner. What is said of the action 
of the suction of the stock as it enters the machine applies in a like 
manner to its work upon it as it leaves it. 

Now, when this stock comes to the smutters or brush machines, the 
same objections are to be met as to the suction, and as to the quality of 
the work when acted upon by the brush or beaters. 1 hey cannot do 
their work properly with this overloading. It means broken wheat, 
which implies a waste and a general abandonment of the idea of scour¬ 
ing and brushing. One often hears it said ol vaiious machines that they 
break the wheat. 

It is the writer’s experience that any scouring machine which will do¬ 
its work properly under careful and judicious management, will bieak 
the wheat when excessively overworked. By this is meant any machine 

(10) 


146 


GRADUAL REDUCTION MILLING. 

which operates with beaters, not brushes; but at the same time it is not 
believed that there is a machine on the market which will break wheat 
when worked to its proper capacity. 

I do not think that the active working miller is responsible for any of 
this. It is the result of custom, rather than of studied neglect. It is a 
course which has had the support of millers for years. I remember to 
have heard it said many times that the wheat did not have to be cleaned 
so well under the new process or gradual reduction methods as under 
the older system of milling, and 1 think it is true that the introduc¬ 
tion of the new systems of milling marked a commencement in the de¬ 
cline in wheat cleaning operations. It is believed, furthermore, that 
the stringency of the times will correct this evil, as well as many 
others which have developed during the periods when the business was 
more prosperous—times when the miller did not have to be so careful in 
order to make a fair profit on his work. In the present condition of 
things there is nothing the miller can do which will add more to the 
value to the bushel of wheat after it is milled than its proper cleaning 
previous to reduction. 

The writer can think of but few mills which would not be materially 
benefited from a financial standpoint by doubling their wheat cleaning 
outfit, and while they are increasing this outfit, it is not impertinent to 
suggest that the attention which is given it should be increased in about 
the same proportion. The “starting up” of the wheat cleaning ma¬ 
chinery is often about all the attention which it receives. The miller 
will start the machines going, put on feed as long as the separators will 
stand it, and pile it through the brush machines and thus to the bins. 
About all the attention that the wheat receives is to see that it makes 
the rounds, to see that the separator screens do not run over, and that 
the brush machines do not choke down. The offal from the latter is 
considered more often in a negative than in a positive way. It is ex¬ 
amined to see if it is too rich, not to see whether it is rich enough. 

If one will keep his eyes open in looking about the majority of mills, 
he will find that the wheat cleaning machines are used merely to run the 
wheat through. It is simply a matter of form. The most attention that 
is given them is to see that they do not d v aw out too much by friction. 
Very little attention is paid to the positive work of the machine. As to 
whether the grain is scoured properly or not, little care is taken. As 
said before, it is simply to get the wheat through. It is purely an inci- 


GRADUAL REDUCTION MILLING. 


147 


dent in the passage of the wheat from the bins to the stock hopper. It 
is a tradition rather than a careful mechanical operation, and the wheat 
cleaning machinery is neglected more than any other in the mill. It is 
the only old process that there is about milling. Everything else has 
been altered and changed, while about all the change there is in 
wheat cleaning in a large number of mills has been in the line of retro¬ 
gression, rather than of progress. Very few of us realize the import¬ 
ance of wheat cleaning. It is an indefinite something which has to be 
done in the natural course of things. We hear it said that Mr. So-and- 
So is a good grinder, or that George is a good hand with the purifiers, 
but do we as often hear it reflected to the credit of these men that they 
are as good hands with the smutter or the separator? It does not seem 
to be so worthy an ambition to be regarded as an expert in handling this 
machinery as it does in the grinding machinery. 

The improper cleaning of wheat means that there is more care and 
attention required in the bolting of the break Hour; more waste of such 
tiourr because of the stock which has to be carried over to lower grades 
and because of its contamination. And then the middlings suffer, and, 
as these high grades are injured, the depreciatory effect is felt in every 
subsequent operation in the process of milling. It should be remem¬ 
bered that as we clean the wheat we are helping to purify the break 
Hour, and that, as we make this hour pure, we make the cut-off and tail 
of the break flour reel cleaner and better, and in this way include the 
intermediate and lower grades of stock. As we clean wheat we are 
purifying middlings, and as we increase the purity of the middlings we 
increase absolutely the purity of the patent Hour. Furthermore, the 
cleaner we get our wheat, the better yield we get, the less hour we get 
in the feed. This comes about by having, as we said before, cleaner 
break stock and cleaner middlings. There is a smaller proportion of 
cut-off from the hour reels and a cleaner quality of stock to go to smooth 
roll reductions. Hence there is less milling to do, less impure stock to 
be handled by the rolls, more hour to be taken off after each reduction, 
less hour to be carried from one reel to another, hence less work to 
be done at the tail end of the mill, less stock out of which to 
make low grade hour, and less stock to go into the feed pile. We see 
that after the wheat is cleaned properly, there is less work for every ma¬ 
chine in the mill to do than if less care were taken with that process. 
We can see that it is difficult to begin too early to work for a yield, and 



148 


GRADUAL REDUCTION MILLING. 

that we can reduce the yield by the proper and more complete cleaning 
of the wheat, and more effectually than we can by the proper and more 
efficient cleaning of the bran when the wheat cleaning is neglected. 

It is not infrequently that we hear of a cleaning machine being taken 
out and replaced by one made by B. On the other hand, we hear of 
B’s being taken out and replaced by A’s, and so on. It may be said 
that one of them is wrong. The chances are that both of them are wrong, 
in that neither should have made the change. After milling machinery 
has been in use for a year or two throughout the country, and so long 
as it is a part of a milling system in vogue, there is no reason for re¬ 
garding the machine as an experiment. No bus ness man is going to 
make and sell a machine any great length of time, if he knows it will 
not do good work, and if he does not know it, some one will find it out 
for him. Therefore, it may be assumed that a miller who will throw out 
a machine which has passed the experimental stages, and which is a part 
of a system in general use, is reflecting more to his own discredit in so 
doing than he is to that of the maker of the machine. One thing which 
the American miller has not learned thoroughly is to do the best with 
what he has; not merely to run his mill without care as to its general 
repair, but to get the very best possible work out of each piece of ma¬ 
chinery in the mill, and not to be constantly wishing and scheming for 
new machinery, changes of system and changes of method. Many 
indifferent millers have kept good positions for a long time by making 
constant changes in the mill. This may appear to be a strange thing to 
say, but it has been done in this way: The miller’s plan is to keep some¬ 
thing ahead of the proprietor’s hopes and anticipations, if this or that 
thing is only forthcoming. When one thing is supplied another is called 
for, and the result is a constant series of hopes deferred. The mill runs 
along, doing ordinary work, and perhaps making a little money, and the 
deficiencies are supplied by promises as to the future. This statement 
of a frequent disagreeable state of affairs is justified by common knowl¬ 
edge. 

It has been the development of practice that middlings could be made 
in the largest quantities by a gradual reduction process. It has been 
further developed that the middlings produced could be best purified by 
gradual means. Now, as exhibiting the utility of gradual operations in 
milling methods, we have to notice the results of gradual wheat clean¬ 
ing operations. During the year 1884 it occurred to a miller that slower 


GRADUAL REDUCTION MILLING. 


149 


and more gradual methods might profitably and effectively be applied 
to the cleaning of wheat, which idea he put into practical operation. 
The lesult was an improvement in yield, a reduction in the percentage 
of low grade Hour, and an advancement in the quality of the higher grade 
products. Instead of passing the wheat over the separators once, he 
passed them over a series of three machines, which had ample capacity 
for handling the stock at each operation. The same thing applies to 
the work of the scouring machine. He submitted the grain, in this in¬ 
stance, to two operations. By removing the material gradually on the 
sepaiatois, he took out nothing else than impurities' small particles 
of wheat and large grains were not removed. By the gradual pro¬ 
cess he w’as enabled to take out all of the impurities, but without re¬ 
moving as large a bulk of material as is usually the case where the oper¬ 
ation is less gradual. He cleaned his wheat better, but removed a 
smaller bulk of material ; he took out only such stock as should be 
properly removed, and did not remove that which properly belonged to 
the wheat, for which reason the bulk of stock was not so large as when 
the operation was more wastefully carried on. In the operation of the 
scouring machinery it is clear that better results can be obtained by a 
repetition of the process. Scouring machinery has been made, the 
operation of which was so severe as to break a large portion of the 
wheat in the effort to scour that portion which was not broken. It must 
be apparent to the miller that the best results may be derived by the 
repetition of a process which is not so severe as in the instance above 
mentioned. The best scouring of the wheat is acquired by a repetition 
of gentle means. 

In the case of the miller who made this change, it may not be out of 
place to say that he made a difference in his yield of more than six 
pounds per barrel, and the percentage of low grade was reduced one- 
third of its original bulk. This was brought about from the fact that 
there was not so much low grade stock in his mill—he took it out on the 
cleaning machinery—and for the reason that such stock was taken out 
at that stage of the process, it is evident that a certain proportion was 
saved from going into a higher grade of dour, as the passage of this low 
grade stock from the head to the tail of the mill would of necessity im¬ 
peril the intermediate grades of dour. It is difficult to emphasize suffi¬ 
ciently the benefits to be derived from the proper cleaning of the wheat. 

It is a common expression in Hungarian mills that investments in 


GRADUAL REDUCTION MILLING. 


i5° 

cleaning machinery always pay. This is said in the face of the fact that 
for many years the Hungarian mills have had the most elaborate and 
extensive arrangements for the cleaning of wheat. The above expres¬ 
sion is still regarded in the light of an axiom, a self-evident truth. While 
the result of the cleaning operations by the Hungarian system is much 
more perfect and altogether more satisfactory than in American mills, 
such success is achieved, for the most part, through the number of ma¬ 
chines used, rather than their excellent quality. With one exception, the 
American wheat cleaning machinery may be regarded as superior to that 
used in Hungarian mills. The exception named is the rolling screen, 
which is largely used in those mills. The American system of wheat 
cleaning, to say nothing about the machines, is very much inferior to 
Hungarian methods. In the Hungarian mills inferior machines are ar¬ 
ranged on a superior system, and for that reason do superior work. 

In those Hungarian mills where so much attention is paid to the clean¬ 
ing of the wheat, it is thought necessary to grade it before submitting it 
to the action of the separators, and a little thought will show the logic 
of such a process. No one ever thinks of purifying middlings without 
grading, and while the difference as to the specific gravity of the wheat 
impurities does not suggest such fine distinctions, thoughtful observation 
will teach us that it will be well to grade the wheat into two sizes. This 
involves the use of a machine which has never been perfected—the 
wheat grader. The only thing which approaches it is the rolling screen. 
The trouble is the lodging of the wheat in the meshes of the wire. One 
of our successful firms who manufacture wheat cleaning machinery at¬ 
tempted to make a grader at one time which involved the use of screens. 
The wheat lodged in the openings, and, thinking to loosen it, they tried 
knockers; but the more they knocked the tighter the wheat was driven 
into the openings. They experimented not a little with graders, but 
never succeeded in making one which was satisfactory to themselves. 
The successful grader has never been made. Our Hungarian friends 
use the rolling screen in default of something better. 






CHAPTER XXVI. 


THE PRINCIPLES OI WHEAT CLEANING—SEPARATIONS—PRINCIPLES IN¬ 
VOLVED IN SEPARATING FOREIGN IMPURITIES—SEPARATION OF 
DUST-THE WEIGH HOPPER—WEIGHING OF WHEAT WITH REFER¬ 

ENCE TO DAILY YIELDS—THE ROLLING SCREEN—THE HORSESHOE MAG- 

NET-THE SMUTTER-REMOVAL OF IMPURITIES WHICH ARE AT- 

I ACHED TO THE WHEAT-GENERAL PRINCIPLES OF CONSTRUCTION OF 

SMUTTERS AND SCOURING MACHINES—GENERAL ARRANGEMENT OF 
WHEAT CLEANING MACHINERY-WHEAT HEATERS. 

In general terms the cleaning of wheat consists in the removal of all 
foreign material from the mass of grain, and the fibre and fuzzy exterior 
from the grain itself. The foreign impurities are the dust, sand, chaff 
and straw. Then there are numerous seeds—chit, wild onions, oats, 
corn and other foreign grain and seeds, as well as blasted kernels of 
wheat and rust, and ergot (smut.) In some parts of the country there 
is trouble from small bits of clay getting mixed with the wheat. There 
are always pieces of metal, such as nails, screws, wire, etc. 

The principles involved in the separation of these impurities and for¬ 
eign substances from the wheat are those used in taking advantage of 
the differences in form, size and specific gravity or magnetic affinity of 
the various impurities. The distinction as to form is taken advantage 
of by passing the whole body of material, grain and impurities alike, 
over a screen, the wheat itself going through openings which are adapted 
to its form. Particles of straw, sticks, chaff, oats, etc., are separated 
from the wheat bv taking advantage of their elongated form. The wheat 
grains go through the screen openings, which are abundantly large for 
their passage, but, as the screen is inclined, each berry must be tipped 
forward in order to enter the hole. Each hole is of such diameter that 
when the wheat grain, sliding forward, carries its center of gravity be¬ 
yond the support of the upper edge of the hole, it drops through. The 
oat grain, or other similarly formed substances, being longer than the 
wheat grain, will, for this reason, extend over the lower margin of the 


152 


GRADUAL REDUCTION MILLING. 

* 

hole before the weight of the lower end is sufficient to cause it to dip 
and fall through. Thus it passes over the end of the screen and goes 
off with the impurities. 

Cockle and other round seeds which are of the same size as the wheat 
are also separated fiom the bulk of the grain, on account of the distinc¬ 
tion as to form. 

One of the earliest devices for separating these round seeds was the 
arrangement of a cone over a cylindrical hopper, the former being 
slightly smaller than the latter. The wheat was discharged at the point 
or upper part of the cone. The elongated wheat grains would slide to 
the bottom of and into the hopper with somewhat less velocity than the 
round seeds. These round grains, how r ever, would slide down the cone 
with much greater velocity than the wheat and le ip over the opening 
between the cone and hopper. This machine is not now in use, how¬ 
ever. Another device consists of a cylinder of partially perforated or 
indented metal. This cylinder is kept in slow revolution. Within 
the cylinder is the trough, which is given a slow, shaking motion, and 
is inclined at an angle of about ten degrees. The indentations in the 
outer cylinder are of such a depth as to allow the small seeds to rest in 
them until the cylinder has revolved sufficiently to allow the small seeds 
to fall back, not into the cylinder itself, but into the rotating trough 
within, the movement and slant of which is sufficient to conduct these 
impurities into a separate spout of the screen. The form of the wheat 
berry does not allow it to imbed itself in the perforations or indenta¬ 
tions of the cylinder sufficiently to carry it so as to fall into this trough. 

The separation as to the Mze of the impurities is made by passing the 
grain over perforated screens, which allow the impurities that are larger 
than the wheat to pass over the end of the screen and the wheat to pass 
through the openings. From thence the wheat passes to other screens, 
with openings smaller than the wheat itself and through which the smaller 
impurities pass. 

The separation on account of the specific gravity may be best de¬ 
scribed by considering that specific gravity is the ratio of weight of 
bodies of equal volume to one another when taken in connection with 
* a standard. Fits of chaff, straw and dust are of less specific gravity 
than wheat; that is, the same volume of such articles weighs less than 
the wheat itself. The separation on account of specific gravity is made 
by passing the entire volume of wheat through currents of air adiusted 




J 5 3 


GRADUAL REDUCTION MILLING. 

-so as to remove all particles of less specific gravity than the wheat itself. 
Aside fiom the dust and chafi, various seeds and impurities, which are 
of the same form and size, though of different weight from the wheat, 
are removed. 

To consider the wheat cleaning operations in more practical form, we 
may say that there is no reason why a certain amount of dust should 
not be taken out of the wheat as it is unloaded, and before it is weighed. 
It could make no appreciable difference in the weight, but it would make 
an appreciable difference, not alone to th se who have to do with the 
weighing, but with the subsequent cleaning as well. Weigh hoppers 
and their surroundings are for the most part disgustingly dusty and dirty. 
More than one man has sacrificed his life by working in this part of the 
mill. If the weigh hopper be in the hopper, as is usual, a great deal of 
the dust could be taken out by merely placing a hooded suction opening 
over the shute. A more elaborate way would be to close the top of 
shute near the mouth in such a way as to get the full benefit of the suc¬ 
tion. This same arrangement is applicable to mill hoppers placed at the 
top of the building. 

Following the wheat from the weigh hopper, it may be said that it 
would be well to remove dust therefrom at every stage in its course pos¬ 
sible, by suction attachments under the weigh hopper connecting with 
the spout which leads from it, and, in case of the weigh hopper being 
below, so that the wheat has to be elevated before being discharged into 
the bins, nothing better can be done than to make a suction attachment 
at the foot and particularly at the head of the elevator. All of this can 
be inexpensively done, and at the same time that it removes the dust 
from the wheat, it keeps the obnoxious material out of the mill. 

It is highly important that arrangements be made to weigh wheat after 
as well as before it is cleaned. Such an arrangement indicates the ex¬ 
act loss in cleaning and tells the story if there be anything unusual. A 
weighing apparatus which makes it possible to weigh each day’s supply 
of wheat separately, enables the miller to take a yield every day, than 
which there is nothing more satisfactory. 

After the weighing of the wheat, it might be passed over a rolling 
screen, on its way to other cleaning machinery. The rolling screen is 
one of the best pieces of machinery which was ever put into a mill, but 
of late years it has been sadly neglected. It went out of use as the new 
process came in ; it died because of its earlier associations. It takes up a 


GRADUAL REDUCTION MILLING. 


*54 

great deal of room—is not very pretty to look at—but it is a fairly good 
separator, and somewhat of a scourer at the same time. With a suction 
fan attachment, all of the dust in the wheat can be taken out. The sep¬ 
arations are made, as is known, by the size of the meshes of the cloth, 
the screenings and small seeds going through the head cloth, the wheat 
through a coarse wire cloth at the tail, and the straws and larger foreign 
material over the tail. The scouring influence spoken of is caused in 
the passage of the wheat through the reel by the friction of the wire. 
This scouring on the rolling screen must not be underestimated. It is 
not sufficient, however, but is just the kind of scouring which will not 
injure the bran, nor mutilate or waste the wheat. If it did not involve so 
long continued an operation, this method of scouring would be an ideal 
process. As to the taking out of the dust, we all know that this is sim¬ 
ple enough. A strong current of air through the reel, preferably from 
the tail, will do the work. 

A rolling screen with a most excellent scouring action may be made 
by using a wire clDth made with square wire rather than round. The 
edges of the wire present a most excellent scouring surface, the severity 
of which could be regulated by the speed of the reel as well as by the 
arrangement of the ribs or lifting surfaces on the inside. By redu¬ 
cing the effectiveness of the latter, the amount of scouring action might 
be largely reduced, and by lessening the speed, the scouring action would 
also be diminished. The general principle of the construction of roll¬ 
ing screens is understood, and, for that reason, it is hardly necessary 
to enter into a detailed mechanical description. 

The following is from a correspondent regarding this screen, and 
is submitted for general consideration: “Its utility or adaptability 
can be nothing more than speculative, as the experiment, as far as the 
writer knows, has never been tried. The suggestion was to have a reel 
into which the grain might be spouted and which would revolve for some 
minutes in it; that is, the supply of wheat would be run into it and then 
cut off, while the reel would revolve A’ith this wheat in it for any desired 
period. This feature would be somewhat similar to the manner of oper¬ 
ating a hominy mill; it would be charged with grain, and after it had 
been in the reel long enough, it would be discharged. It would have to 
be arranged so that the reel would be level while the g ain was in it, and 
pitched at a time when a discharge was desirable. Again, it was sug¬ 
gested that there might be automatic arrangements for supplying the 
reel with the proper quantity of grain. ” 




GRADUAL REDUCTION MILLING. 


*55 


It is easy to see that the grain, when run into a reel clothed with wire 
and retained there for a time while it was in motion, would be well scoured. 
There would De the friction of the grain against itself and against the 
wire and ribs, which operation would not be so severe as to, in any way, 
disturb the bran coating. In fact, the severity of this operation might 
be regulated in many ways. We know that there are means of redu¬ 
cing grain by attrition, by the force with which it is propelled against any 
hard surface. This is the extreme of a movement of this kind. Again, 
we know that the grain might be put into a reel with a smooth inside 
surface which revolves slowly, and which would have very little effect 
upon the grain. Here are the two extremes. 

The object in charging a reel and allowing the stock to stay in it for 
a time is to increase the duration of the friction, but not its absolute 
severity. Smutters and scouring machines, as ordinarily arranged, may 
be either too severe or not sufficient in their operations. It is desirable, 
by most millers, that the work of wheat cleaning be done quickly, with¬ 
out great expense in money or time. In the effort to make machines of 
great capacity and apparent efficiency, many of them are too severe. 
One or two scouring machines, where the wheat merely passes through 
them, must of necessity act harshly if they appear to scour the wheat; 
or lightly or inefficiently if they are not severe and yet are hasty in their 
operation. A miller could scour his wheat as much or as little as he 
pleased by controlling the length of time that it was in the reel and, at 
the same time, not injure the bran. 

In any cleaning operation a certain proportion of the outer layer of 
the four layers of the bran coating will be removed. Attached to this 
bran layer and the next one are the vegetable hairs at one end, and the 
scale surface over the germ coating at the other. Wheat cannot be said 
to be properly scoured until both the vegetable hairs and this scaly sub¬ 
stance at the other end of the berry are removed. The wheat, after be¬ 
ing properly scoured, will show a round end with a crease through the 
centre, instead of the elongated form which was given it by the vege¬ 
table hairs. Work of this kind, when done thoroughly, is frequently done 
at the expense of a large amount of broken wheat and lacerated bran 
coatings. The less severe methods do little or nothing in a proper way. 
These latter methods, if repeated, or if they could be made to operate 
on the wheat during a longer period, would be the most efficient and 
satisfactory. The method which contemplates the charging of the reel 


!5 6 


GRADUAL REDUCTION MILLING. 


in the way described would necessarily require more machines than the 
usual way of scouring wheat, but the cost, certainly, would not be pro¬ 
portionately greater, either as to plant or as to the power required in 
their operation. These machines would probably require more space, 
though not a great deal more. The operation would not have to be re¬ 
peated. 'The miller could arrange to keep the wheat in the reel until it 
was scoured. Thus there would be only one operation, though there 
would probably have to be two or three machines to do the work of one, 
as to capacity as estimated by the amount of stock required in the mill. 
That is saying nothing about the quality of the work. 

One of the most positive separations which is made in the cleaning of 
wheat is by the use of the magnet. It was brought prominently into 
use immediately after the introduction of wire binders, and it was found 
that even with wheat, in the harvesting of which self-binders had been 
used, the proportion of wire removed was by no means the largest 
quantity of metallic substances which were taken out. Whether the 
magnets be of the ordinary horseshoe form, or the very neat and effect¬ 
ive mechanical arrangements known to us all, it is well that they be used 
before the wheat goes to the separators or rolling screen and again 
immediately previous to its entrance to the first reduction bin. Mag¬ 
netic separators are so inexpensive that a miller can well afford to be 
somewhat prodigal in their use. 

The impurities which are attached to the bran are the vegetable fibre 
and hair, which are a natural part of the growth of the wheat. Such 
impurities, and the smut, which is of the same size and specific gravity as 
the wheat itself, are removed by the smut and scouring machine. The 
impurities which are attached to the bran should be removed without 
disturbing the general bran structure itself. The attempt was made 
some years ago to entirely remove the bran from the exposed surface of 
the berry previous to its reduction. Machines for doing this work were 
called decorticators, the idea being that if the bran could be removed 
the wheat might readily be reduced and the flour bolted without getting 
into it the usual proportion of bran particles. But the result was ex¬ 
actly the opposite; there was a larger proportion of bran particles in the 
flour and middlings than ever before. Instead of improving the fiour 
and middlings, the decorticating effort largely depreciated the value of 
the milling product. In practice only a part of the exposed bran sur¬ 
face was removed, and that part which was in the crease of the berry 


GRADUAL RbDUCTION MILLING. 


1 S7 

could not be touched. As a matter of practice it has been developed 
that any effort at wheat cleaning, or any preparation of the wheat pre¬ 
vious to its reduction by reduction machines, which breaks or disturbs 
the bran structure, is a detriment to the product of the mill. It is im¬ 
portant that the bran be allowed to retain all of its natural strength and 
toughness, so as to resist the pulverizing action of the reduction ma¬ 
chine. In scouring wheat by the ordinary methods it should be remem- 
l ered that only a mild polishing of the bran surface and the removal of 
the fibre therefrom is desirable, and that anything which attempts to go 
further than this is seriously objectionable. 

As to the general construction and operation of smutters, it may be 
said that the principle of their operation is the same in all, the idea be¬ 
ing to remove the attached impurities by friction; and the only differ¬ 
ence in the construction of the various machines is in the variation of 
the mechanical arrangement for submitting the wheat to this friction or 
scouring action. 'They are all constructed with the same mechanical 
idea of a cylindrical perfora v ed surface with internal revolving friction 
surfaces. With the latter the variation is in form, material and arrange¬ 
ment of parts. There are blades and round beaters; there are discs 
and revolving feeders, or surfaces, which rub the particles of grain to¬ 
gether and against the jacket and the feeders themselves. As to the 
material out of which these various friction surfaces are made, there is 
iron, wrought and cast; steel, stone and brushes. 1 his material is ar¬ 
ranged in the form of discs of the various materials, which revolve 
against one another and which are arranged horizontally, they being 
arranged so that in some instances iron and stone operate togethei, and 
in other instances iron and the brushes. I hen again, there are the 
vertical revolving brushes, both open and solid, and theie is also the 
combination of vertical beaters and brushes. I here aie machines of 
somewhat different construction which hold the wheat in the jacket and 
rub the particles of grain one against anothei, teeding it out at the bot¬ 
tom in such a way as to keep the jacket above partially full ol giain at 
all times. This arrangement causes the jacket to serve as a magazine 
receiver which retains a charge of grain within it at all times. 

The jackets themselves vary somewhat in construction, being made, 
for the most part, of perforated steel, though wire netting and surfaces 
with interior protuberances is used on some of the machines. By the 
operation of the various friction devices, the attached impurities ot the 


GRADUAL REDUCTION MILLING. 


158 

wheat are separated therefrom and the suction draws such particles 
through the jacket and forces it from the machine. At the same time 
that these impurities are removed, the particles of smut and brittle grains 
are broken, which operation makes the particles lighter, and changes 
the gravity, so that they may be drawn out by the suction. All scour¬ 
ing machines perform the same general office of separators. The wheat 
is submitted to a suction before going to a machine, during its passage 
through it and finally as it leaves it. 

It is well known that smutters are regarded as one source of danger 
from fire in flour mills, owing to the liability of the beaters to strike fire 
by coming in contact with pieces of metal. This can be entirely obvi¬ 
ated by the use of phosphor-bronze in the construction of the beaters 
and jackets. The beaters and pickers of the cotton mills were formerly 
a great source of danger, and caused the destruction of many factories 
in that way. Since the introduction of phosphor-bronze, losses from 
that source have been reduced to a minimum. 

Before leaving the question of wheat cleaning we will consider, in 
short form, the general system of arrangement which may be ordinarily 
used. First, perhaps, the magnets for removing metallic substances, 
after which the wheat may pass through a rolling screen that will do a 
certain amount of scouring, and which will also remove all of the larger 
and coarser impurities and a certain amount of the screenings. Then 
comes the separators, which remove a certain other proportion of the 
foreign impurities, including a large volume of the screenings and dust. 
From the separators the wheat goes to the cockle machines, which re¬ 
move the round seeds and small broken particles of wheat. In order 
that the proportion of the latter may not be too large, it is preferable to 
have the cockle machines come after the separators rather than after the 
scouring machines, as in the latter event all of the wheat broken by 
these machines would be taken out by the cockle machines, which would 
be a great waste. There are arrangements of cockle machines which 
have, as a part of the same machine, a separator—a very compact and 
economical arrangement for small mills. Of all machines used in con¬ 
nection with the wheat, none are more wasteful and at the same time 
more inefficient when overworked than the cockle machines. In cer¬ 
tain sections of the country cockle does not grow in sufficiently large 
quantities to justify the use of the machine for making these separations. 

After the grain leaves the cockle machines it passes to a scouring ma- 




GRADUAL REDUCTION MILLING. 


*59 


chine of a more severe type, which removes, by suction, certain foreign 
impurities which were not taken out by the separators, and which also de¬ 
taches the fibrous impurities from the grain and disintegrates the softer 
and smut particles which are taken out by a suction fan. Following the 
smutters and scouring machines of the more severe type are the brush 
machines, after leaving which the wheat is taken to the bins, where we 
will leave it for the consideration of the subject of wheat heaters and 
artificial moistening apparatus. 

After the wheat has left the cleaning machinery, and before it goes to 
the reduction machines, it may pass through steamers and heaters. In 
some parts of the country it is found necessary to wet the wheat before, 
it is reduced, on account of the brittle nature of the bran. Because the 
wheat is dampened it does not follow that the Hour or middlings will be 
damp. The process is so timed that, while the wheat will be uniformly 
moist, the moisture does not have time to enter the body of the berry and 
affect it wrongly; it simply toughens the bran. The wetting of the 
wheat is accomplished oftentimes by a conveyor which thoroughly mixes 
it, and from whence it goes into a bin, to remain long enough to become 
uniformly and duly moistened. The advantages to be gained by tough¬ 
ening the bran by moistening the wheat either by steam or water, or by 
drawing the moisture from the centre of the berry by heating, is one of 
degree. It will be appreciated most where the wheat is most brittle. 
It will have a beneficial effect upon any wheat, most beneficial, of course, 
where the bran is least tough. 

Excepting in exceedingly dry countries, or where the bran is extremely 
dry and brittle, the heating of wheat will usually bring a sufficient amount 
of moisture from the interior to the exterior of the wheat to toughen 
the bran and do all that may be done for it in this way. 

A wheat heater will not make tough wheat dry, nor dry wheat partic¬ 
ularly tough, but it does have a quality of bringing about a more uni¬ 
form condition of the stock. As far as is known, there is no condition 
of the wheat, if it is at all suitable for grinding, but that ite product will 
be improved by its having been passed through the heaters. The bran 
will be larger, the flour clearer, the middlings rounder and freer from the 
bran specks, and more easily purified on that account, the flour moie 
easily bolted, because of its freedom from the contaminating influences 
•of the impure material. 

There is a smaller proportion of middlings from wheat thus treated 


l6o GRADUAL REDUCTION MILLING. 

which has pieces of bran attached. This is because the bran is less 
brittle, coming off in larger pieces. This is one reason why the mid¬ 
dlings are more easily purified, and it is a very good reason why there 
is a smaller proportion of tailings from such middlings. Probably 
every miller has noticed that the proportion of small bran particles 
and other undesirable stock is much less with tough wheat than with 
that which is extremely hard. Wheat which has passed through heaters 
has the virtue of being dry on the inside and tough on the outside. It 
will always be noticed that such wheat feels a little damp. Now, there 
is no place for this dampness to come from except fiom the inside 
of the berry, and if this dampness or moisture is perceptible on the out¬ 
side of the grain, it cannot be present to so great an extent on the in¬ 
side. Hence, it is reasonable to suppose that the part of the wheat 
which it is most desirable to reduce—that is, the inner portion—can be 
most readily reduced, and that the exterior, which it is desired not to 
reduce, is tougher and less susceptible to the action of the reduction 
machinery—a very desirable condition of things. 



CHAPTER XXVII. 


FIRST BREAK—WHEAT GRADING FOR GRINDING-GRADING OF WHEAT ON 

ACCOUNT OF HARDNESS OR SOFTNESS-WHEAT MIXING—PURPOSE OF 

WHEAT MIXING-MACHINERY OF THE FIRST REDUCTION—FIRST BREAK 

SCALPER— FIRST BREAK FLOUR—CREASE DIRT—THE SCOURING ACTION 

OF THE FIRST BREAK SCALPER-FIRST BREAK AS PREPARATORY TO 

MIDDLINGS MAKING-CLOTHING OF THE FIRST BREAK SCALPER- 

CLOTHING OF THE FIRST BREAK FLOUR REEL-FLOUR FROM THE FIRST 

BREAK-PROPORTION OF FIRST BREAK FLOUR. 


As suggested by the foregoing chapters, it is the purpose to take a 
look through the mill, taking each reduction and the separating machin¬ 
ery which immediately follows it, and making such observations and 
notations as such a course would naturally bring out. 

Before taking up the wheat where we left it, it will be in order to con¬ 
sider the matters pertaining to its grading or mixing previous to its re¬ 
duction. 

There has been a great deal of talk about the grading of wheat. It 
has its theoretical and practical advantages. There are small and large 
grains of wheat in a general mass, and it is only the larger grains which 
receive the benefit of the first reduction. If the rolls are set properly 
for the large grains, they are too open for those which are smaller, or if 
they are set properly for the small grains, the large ones are reduced too 
much. If there is a compromise, none but the medium sized grains are 
properly handled. There are very few mills that are carrying out this 
idea of the grading of wheat previous to its reduction. There are few 
millers who do not recognize good reasons for so doing. The greatest 
practical obstacle in the way of accomplishing this result is that the suc¬ 
cessful grading machine—the one that is generally recognized as being 
successful—has not been made. The great difficulty is in keeping them 
from clogging. Whenever this is gotten over, the grading of wheat will 
be more common in mills which employ more than one pair of rolls for 
the first reduction. It is not necessary to carry the division of stock 
(id 


GRADUAL REDUCTION MILLING. 


162 

made necessary by the original difference in size further than the first 
break. In any event the first break is a sizing operation. 

On the same line it may be well to say that it is theoretically wrong 
to mix wheat for grinding, though it is for the most part a practical 
necessity. At one time the following expression was made use of in 
this connection: “Of all the unreasonable, pernicious practices in mill¬ 
ing, that of mixing wheat is the most to be wondered at. If a miller 
knows what he wants most, he knows that he wants wheat of a uniform 
texture; that is, uniformly hard or soft. * * * * Flour mixing is 

all right, and wheat mixing all wrong.” This is all right; but there are 
circumstances which compel the millers to mix wheat previous to grind¬ 
ing. The mixing of Hour in a mill in exact proportions is not a very 
simple matter, and there are many millers who always see fit to grind 
hard and soft wheat together. For instance, in the winter wheat coun¬ 
try it may often be desirable to mix in a certain proportion of hard, 
small Kansas wheat, which, by the way, makes most excellent Hour, with 
a certain other proportion of round, soft Fultz wheat. Now, in the 
grinding on the first break, many of these small grains will not be 
touched unless the larger grains be very much lacerated by the close 
setting of these rolls. One way out of this difficulty where there are at 
least two pairs of rolls on the first reduction, is to grind the small, hard 
wheat on one pair of rolls, and the Fultz wheat on the other. This 
would involve a division in the first reduction bin so that the hard and 
soft wheat could be kept separate previous to grinding. Each grade 
could be smutted separately; that is, at different times. In this way the 
two grades of wheat, after passing through the rolls, would run together, 
and further on in the process of manufacture they would continue to¬ 
gether. But this separate grinding on the first break will partially miti¬ 
gate the evil of handling hard and soft, large or small wheat together. 
It is a fair venture to say that there is more mixing of wheat both in the 
spring and winter wheat sections at this time than ever before. In the 
winter wheat region it is the mixing of hard and soft winter wheat; in 
the Northwest it is the same thing with the different varieties of spring 
wheat, and in both instances it is brought about by the scarcity and 
superiority of the harder varieties. Notwithstanding that the mixing of 
wheat is not exactly the thing to do, it will be done a great deal more 
than the mixing of flour after its manufacture. The mere mixing of one 
product with another is usually done in this country with a conveyor, 





i6 3 


GRADUAL REDUCTION MILLING. 

which is quite efficient. In Hungarian mills, and in a few mills with us, 
it is done by a revolving disc under a stationary one, each having wooden 
pins projecting from each surface. 

To take up the first break: The express purpose of this break is to 
split the wheat in order to release the crease impurities. The writer 
will say that he has never seen a reduction machine which did this thing 
with any degree of completeness. It is fair to say that a good propor¬ 
tion of the grains are split, but not all by any means. There are many 
grains with the backs and ends knocked off and many which are cut 
lengthwise, but there is not that proportion of wheat which is split 
through the crease that is desirable. However, this end may soon be 
reached, as very many intelligent millers and mill builders are working 
for a better first break machine. 

With roller machines there are means and arrangements for the express 
purpose of making a satisfactory first break. The writer has lately heard 
of two rolls with very coarse corrugations, say two to the inch. Then 
there are machines with one of these coarsely corrugated rolls running 
against a smooth roll. The experiment has been tried of running sharp 
cut rolls of the ordinary corrugation—eight to the inch—at integral mo¬ 
tion ; that is, both at the same speed. The more common way is to run 
such rolls two to one, the sharp part of the corrugations together. A 
very fair break with sharp cut rolls can be made by running the dull 
backs together. This can be done by running what is ordinarily in¬ 
tended for the slow roll, fastest. 

It is a common expression that the iron disc machine makes the best 
first break, but while this may be so, it is also true that it makes more 
flour than is made by rolls. 

A miller described to the writer a machine which was tried. It was 
a form of disc machine similar to the Jonathan Mills, but different in 
dress; it had furrows, in form thus There was no draft 

except a very little at the skirt. He said that it worked very well— 
split the wheat—but made entirely too much Hour. 

A satisfactory first reduction by any machine can never be made un¬ 
less the wheat is graded, for whereas, four corrugations to the inch is the 
proper number for the largest grains of wheat, or for wheat as it goes on 
to the rolls in an ungraded condition, it is fair to say that smaller cor¬ 
rugations—say six to the inch—should be used for smaller wheat. This 
is where smooth and corrugated rolls run together. 


164 


GRADUAL REDUCTION MILLING. 

After the stock leaves the rolls it goes to a reel clothed with 18 and 
20 wire. Sometimes a sieve has been used; but whatever preference 
one might have for a sieve elsewhere, it cannot be said to have a place 
as a first break scalper. A reel three feet long will make a complete 
separation for a 500-barrel mill on soft winter wheat, and one two feet 
long would do the same thing on a 100-barrel mill, though it would not 
give the scouring and detaching action which was mentioned in connec¬ 
tion with this reel. Two feet might be a little short where the wheat is 
spouted into the reel in such a way that it does not discharge close at 
the head, but it would be safe to say that where the stock has full benefit 
of the two feet of reel, it would no doubt do its work well as to scalp¬ 
ing, but would do little scouring. 

The motion of the reel is inclined to assist the work of the rolls in 
that it will separate the pieces of wheat that remain together after leav¬ 
ing the rolls, and which have not been entirely broken thereby. This is 
one place where the work of a disintegrator is useful, and a reel answers 
this purpose very well. It completes the unfinished work of the rolls; 
it jars the pieces of wheat apart and liberates the crease impurities, as 
well as the middlings. Some one advises the use of a centrifugal reel 
for this purpose, and there is mention made of where such reels have 
been used as smutters, covering them with steel wire cloth. 

It has been questioned many times whether the flour from the first 
break was really of the objectionable character usually attributed to it. 
An examination of the flour certainly ought to settle this question. We 
know that it makes a muddy, black dough, without any of the qualities 
of good flour. As to the seam dirt, the writer is inclined to think that 
it is there, the form of the receptacle being such as would retain dirt 
and dust. It is certainly such as would render it difficult of access by 
the ordinary cleaning machinery. If it is desirable to scour the more 
accessible portions of the grain, it is certainly desirable that those less 
• accessible should be treated in the same way, in so far as it is econom¬ 
ically possible. It is possible in so far as the first break will split the 
wheat, and the first break scalper will scour it. The splitting of it, and 
the general disturbance of the berry by being crushed, is calculated to 
release the crease or seam dirt when it is first submitted to the action of 
the reel. The first break scalper is a good deal like a rolling screen. It 
screens and sifts the wheat after it has been submitted to the first reduc¬ 
tion rolls. For this it is a most valuable machine. It is a scourer to a 





GRADUAL REDUCTION MILLING. 165 

great extent in the nature of its construction. On account of this 
scouring action the flour made by the first break rolls and in the reels 
will be bad. The scourings go into the first break Hour and the quality 
of this Hour indicates the action of the first break scalper as a cleaning 
machine. 

Aside from the merit of the first break operation, as here suggested, 
there is the additional merit of its quality as a preparatory machine. 
Even if it did not remove any of the dust or bad flour, or that the first 
break scalpers did not scour the wheat in any degree, in fact that there 
was no immediate result from its use, it would still be a necessity for 
gradual reduction milling; it would be a necessity as a reduction ma¬ 
chine. It splits and breaks the wheat in away suited to the action of 
the subsequent reduction machinery. The second break does the same 
thing in a measure. After the wheat has been broken and split in the 
coarse way that it is by the first break, it is then possible for the finely 
corrugated rolls to reach the stock in a way to separate the Hour and 
middlings therefrom. This is a merit of the first break machine which 
has not always been appreciated, and the more it is thought about the 
more it will be appreciated. 

All this suggests that a reel slightly longer than is absolutely neces¬ 
sary to make the separations might do good work as a scalper for this 
break. It would knock loose a good deal of dirt, and continue the 
work of the wheat cleaning machine in a mild way. This idea is used 
in the dismembrators, and in various other machines in connection with 
the reduction. 

In a previous chapter mention was made of the relation which the 
corrugations bear to the clothing of the scalping reels. The size of the 
middlings is determined in a large measure by the size of the corruga¬ 
tions, and as it is desirable to take out the middlings as fast as they are 
made, the reels should be so clothed that they will not carry over mid¬ 
dlings from one reduction to another. It is fully developed that No. 20 
wire cloth will not carry over middlings to the next reduction, when 
rolls with ordinary corrugations are used on whole wheat. This, of 
course, covers its use on the first reduction. At the same time that No. 
20 and 22 wire will not carry over middlings as mentioned, any finer 
number would. No. 18 wire is used a great deal on the fust bieak, but 
the middlings which go through such a number are equal to those of No. 
0000 silk, and there are very few mills which have facilities tor taking 


166 


GRADUAL REDUCTION MILLING 


care of so large a grade of middlings. It is embarrassing and unsat¬ 


isfactory to try to do anything with them when niixed with smaller mid¬ 


dlings. In truth they are very lumpy, being ends of wheat or small 
bits of middlings with large adhering portions of bran, which bran de¬ 
termines their grade rather than the middlings themselves. If one were to 
examine middlings which pass through a oooo cloth, he would see a very 
small proportion of pieces which did not have adhering portions of bran. 
In fact, such bran gives color and character to the whole product. Ad¬ 
hering bran is the rule and not the exception. They are nubs rather 
than middlings. 

The product of the scalping reel, which is flour and middlings, is 
usually and preferably cared for by itself. By this is meant that the 
flour is bolted and sent to the packer and the middlings sent to their 


proper place in the mill for the 
purpose of grading and purifica¬ 
tion. The work of taking care 



6 HO 8 + 1 


of this product is often done on two reels, but still more frequently on 
one. The reel is clothed, when only one is used, in many instances as 
shown in the accompanying cut. 


The product of the flour cloth is low grade. The cut-off of the flour 


cloth and the product of the No. 8 or 9, is a low grade of dust mid¬ 
dlings, which makes a low grade of bakers’ flour. The tail of this reel 
is good middlings, which may well be sent to the grader. When two 
reels are used, the middlings should first be scalped over an 8 or 9 cloth, 
and the flour cloth on the next reel below. Oftentimes the product of 
the scalping reel as mentioned, i. e.,_that clothed with No. 8 or 9 cloth, 
is sent with the sixth break stock to be bolted. This is objectionable 
because, as a general thing, the flour is poorer from the first than the 
sixth break, and further, because the middlings which will go through a 
No. 8 or 9 cloth are a better grade in the case of the first break than is 
the case with the corresponding or larger middlings of the sixth. The 
flour from the first break varies in quality with the same grinding and 
the same general grade of wheat. Winter wheat immediately after har¬ 
vest makes better first break flour than later in the season. This is the 
case even though the wheat be quite dry and hard at the beginning of 
the crop year. Soft wheat makes better first break flour than hard wheat. 

There is really a very small proportion of flour made on this break. 
When gradual reduction methods were first introduced, we were led to 








GRADUAL REDUCTION MILLING. 


167 


believe that 3, 4, and even 5 per cent, of the break hour was ordinarily 
made at the first reduction. By grinding ordinarily close, 1 per cent, 
of fiour is more than is usually made in this part of the mill. The pro¬ 
portion of flour made by rolls with corrugations as coarse as those here 
used is not in the ratio of their close setting when grinding. It is not 
possible to make a very large proportion of flour with such coarse cor¬ 
rugations. 

Various methods of arranging first break machines and the reductions 
which follow will be indicated in the practical operation of such ma¬ 
chines and their following uses in the mills of specified sizes, which will 
be considered in future. In that way the methods which are adapted 
to the various sized plants will be properly understood and properly 
followed up by the subsequent operations. 


CHAPTER XXVIII. 


SECOND REDUCTION—PROPORTION OF FLOUR FROM THE SECOND REDUC¬ 
TION-ZINC FOR CLOTHING SCALPERS-PROPORTION OF BREAK FLOUR- 

DRESS OF SECOND BREAK ROLLS—SCALPING FOR THE SECOND REDUC¬ 
TION-ASPIRATOR FOR REDUCTIONS—RUNNING OF THE SECOND BREAK 

ROLLS WITHOUT A CHANGE OF FEED. 

After the stock leaves the first break scalper it frequently goes through 
an aspirator on its way to the second break machine. '1'hese aspirators 
are constructed like the aspirating middlings purifier, though they do 
not need to be so fine in adjustment. This machine may take out a 
little light bran, though very little, not much of it being detached dur¬ 
ing the first reduction. But if there should be any wheat which had not 
been separated from the heads or chaff in threshing, the first reduction 
will complete this work, and the aspirator will draw out the white caps 
But really there is not a great work for the first break aspirator to do, 
the reduction not being severe enough to detach any of the impurities 
of the wheat which would not go through the scalper. 

The second break operation is a middlings making as well as a pre- 
paratoVy process. Very little flour is made by the rolls on either the 
first or the second breaks. More Hour is made in the reels and eleva¬ 
tors than on the rolls. This matter is deserving of careful attention. 
As a middlings making process, every detail of gradual reduction should 
have in mind not only the making of middlings, but the means of pre¬ 
venting the making of break Hour during the process of wheat reduc¬ 
tion. As there is no difficulty in making the Hour and middlings sepa¬ 
ration from the second break stock, it cannot be seen why a sieve sepa¬ 
ration would not be possible. The position for such sieves might be 
under the rolls, to avoid the use of elevators, and hence little fiour is made 
in this way. Zinc is being used to some extent instead of wire for cloth¬ 
ing all scalpers following the first break. It can be recommended for 
general use. 

Considerable has been said about the second break and its import¬ 
ance as a milling operation, not exactly on account of its value in its 


GRADUAL REDUCTION Mil.LING. 


169 


production of middlings or flour, but in a preparatory way in getting 
the stock ready for the third and fourth breaks. Because the results of 
the second break are not apparent during the immediate course of, or 
in connection with its operation, it is not deserving of neglect. It is a 
matter ot the greatest importance that the grinding by the second break 
rolls be attended with great care, as the whole product of a mill is 
largely influenced thereby. 

We often see tables wherein the exact proportions of flour and mid¬ 
dlings made by the various breaks is given with the strictest regard to 
accuracy of expression. Figures are given, including two and three 
decimal points, indicating that the weighing and measuring has been 
done in a very scientific manner. Excepting in general terms and in a 
geneial way, the writer has never been able to determine the quantities 
of flour made by the various breaks. He has never done any weighing 
or measuring for the purpose of informing himself, and cannot think 
that the figures which we see given for the purpose of determining the 
quantities of flour made in this way can be of practical service, as there 
must be a great deal of variation with the different kinds of wheat, and 
with the same wheat under different conditions and circumstances. In 
one mill the break stock may drop into a conveyor and be carried some 
distance before entering an elevator that conveys it to a scalping reel, 
which may be somewhat longer than necessary. The conveyor, its 
length, the elevator, the spouts leading therefrom, the reel and its con¬ 
struction, may be largely instrumental in influencing the proportion of 
flour made by the breaks. Thus a miller may be doing just as good 
work on the rolls, independent of the other devices, and yet if he were 
to take the pains to determine how much break flour he was getting 
through the reels from a certain break, it would be shown that he was 
not doing satisfactory woik, when compared with the standard set forth 
under more favorable conditions. The proportion of grinding surface 
on the rolls, their speed, the dress, all largely influence the proportion 
of flour made; and as there is such a great variation in all these things, 
and as millers are operating under such a variety of conditions, it is 
difficult to see how they can be greatly benefited by the elaborate exhi¬ 
bitions which are the result of ideal conditions, and which are expressed 
in a very scientific way. 

Any one who has ever done any sifting for the purpose of making 
experiments, knows how deceitful that process is. He knows that he 


GRADUAL REDUCTION MILLING. 


I 70 

can always get better results with a hand sieve than he can get with the 
reels in his mill in a practical way. Take the sixth break, for instance. 
By sifting the stock one can get some very brilliant flour, yet as it comes 
from the reel it is far from brilliant. It may be white enough from win¬ 
ter wheat, in the dust, but it is very red in the dough. In sifting the 
second break one finds very little Hour, and that of questionable qual¬ 
ity. The flour from the second break does not look as well as that from 
the fifth. The middlings, however, are of good quality, both as to gen¬ 
eral appearance and form. 

Some time since the writer made up his mind that ten corrugations to 
the inch was the proper thing for the second break, and having used 
both ten and twelve, is still persuaded that the former is the best. Such 
a corrugation cannot make a great deal of Hour, no matter how close 
the grinding; and whereas, it is not desirable to grind close on this 
break, there are circumstances which demand closer work one time than 
another, both in the first and second breaks. This is when the wheat is 
soft. The first break is more of a purification than the following wheat 
breaks. The second break makes large, heavy middlings, and a small 
proportion of flour. The grinding on these two breaks has a great deal 
to do in influencing the quality of the work done on the subsequent 
breaks. When the wheat is soft, as intimated before, it requires that the 
grinding be closer in order that the third, fourth and fifth breaks may 
not have so much to do that they will make soft, flat middling-. 

The scalping reel for the second break should be one-third longer than 
that for the first. An eight-foot reel will do the work on a 500-barrel 
mill. Three or four feet will do for a 100-barrel mill. The length of 
the scalping reel for any break is dependent upon the proportion of soft 
stock going into that reel, and for a mill with four breaks which makes 
100 barrels of flour per day, as is often the case, longer scalpers would 
be required than are here specified. Owing to the greater amount of 
work required of each reduction, and consequently the larger propor¬ 
tion of flour stock made, a larger reel would be necessary. It is quite 
common to build scalping reels all in one chest, and consequently all 
of one length. There cannot be good reason for this, as a reel which 
would be long enough for the third or fourth break would be too long 
for the second and not long enough for the fifth or sixth. Or, if they 
were long enough for these breaks, they would be too long for the others, 
and as has been said before, it is nearly as important that the scalping 


GRADUAL REDUCTION MILLING. iji 

reels after the first break should not be too long as that they should be 
long enough. If too long, they would whip through fine bran and other 
impurities at the tail, besides making flour in the reel. 

As a ten corrugation will make a good many ooo middlings, and as 
ooo middlings from the second break are bright, if of good quality, it 
suggests the clothing of that scalping reel with No. 20 wire cloth, which 
was the same as used for the first. One might say that if a second 
break with ten corrugations requires a No. 20 wire cloth on the scalping 
reel, the eight or coarser corrugations of the first would demand coarser 
than 20 wire for the first break. It would if coarser middlings than 
the ooo were desirable in the mill. The 0000 middlings, which would be 
equivalent to those of an 18 wire, as said in the foregoing chapter, have 
large adhering portions of bran, and are not of a quality readily dis¬ 
posed of in the manner usual with middlings. No. 20 wire was used 
for the first break on this account, but if the natural demand of the cor¬ 
rugation had been considered, without reference to the quality of the 
middlings, 18 wire would have taken its place. No. 20 wire is the nat¬ 
ural demand of ten corrugations, and as the product of middlings from 
that number is desirable, it is so clothed. The product of the second 
break is bright, clean stock when the preceding first break has been run 
sufficiently close. 

Two or three years ago, when the stock from the various breaks was 
under discussion, a miller was advised to bolt his third and fourth break 
chop together after leaving the scalper, and the second and fifth by 
themselves. This was in a large mill, where it was possible to do 
this if there was any advantage to be gained by such an arrangement. 
This was not right. If there are to be any divisions at all of this kind, 
as there may profitably be in a large mill, it does not want to be done 
by running the second and fifth break stocks together. As a matter of 
fact, there are no two breaks which are alike. The third and fourth are 
the nearest, but the others are widely different one from the other. It 
would be better policy to handle the second and third break together 
than it would the second and fifth. But the second, third and fourth 
are near enough alike to be handled together in separating the Hour and 
in the purification of the middlings. This part of the description will 
be handled later. The Hour from the second break is white and granu¬ 
lar. It has a rounder, sharper feeling than that of any other break. 

The stock passing over the tail of the second break scalper goes to 


1 7 2 


GRADUAL REDUCTION MILLING. 


the third break, of course. In some instances it passes through an as¬ 
pirator. The idea of an aspirator is to take out the light, fine stock, 
and thin, fly-wing bran which may be detached during the process of 
reduction. In the later reduction there may be some finished bran to 
be taken out, which, if continued to the end, would be cut up and thus 
be injurious to the flour made by these machines. In fact, this would 
be the case in the reduction of any of the impurities which were speci¬ 
fied as being such as it was desirous of taking out by the aspirators. 
These machines are nothing more or less than purifiers. 'They take out 
the impurities which are of less gravity than the unfinished break stock. 
They remove the stock which should not go in with the subsequent 
breaks. They take out unfinished feed which would otherwise be pul¬ 
verized with the Hour. But there is another side to this question ; at the 
same time that they take out these impurities they draw out Hour and 
mix it with the undesirable stock, or blow it into the dust room. One 
might say that there should not be flour in the stock which tails over 
the scalpers to go to the aspirators. But the fact of the stock showing 
clean as it leaves these reels does not necessarily imply that it does not 
contain flour in a shape to be taken out by the aspirators. 'The unfin¬ 
ished break stock may have this flour inclosed in the various particles 
composing that stock, and which was not disturbed or knocked out in 
the reels, but when submitted to the action of a suction fan, will come 
out in surprisingly large quantities. One of the purposes of a dismem- 
brator is to open up the stock and make the separation which is not 
made in a common reel. 

Here again comes the query whether or not the dismembrator or agi¬ 
tator does not mix a dangerous proportion of the impurities of the wheat 
with the flour and middlings stock. As opposing the idea of a dismem¬ 
brator or even the action of a reel, is the sieve scalper, which is cer¬ 
tainly the gentlest means of making a separation. The Smith Purifier 
Co. formerly made, and may be making now, what they call a break 
purifier. The idea was certainly a good one as they arranged it. After 
the stock left the rolls it first went through a reel to take out the flour 
and finest middlings, say that which would pass through a No. 3 or 4 
cloth. The part which tailed over this reel went onto the break puri¬ 
fier mentioned, which is similar to the Smith Middlings Purifier, though 
not so elaborate in detail. This machine aspirates and grades the coarse 
middlings at the same time it takes the impurities formerly mentioned 


173 


GRADUAL REDUCTION MILLING. 

from the stock which goes to the next reduction. This is a good scheme 
and ought to work well if properly arranged and worked out. 

A miller with whom the writer was talking several months ago, said 
that he never changed the feed gates on the second reduction, as he 
changed it on the others to conform with this. His idea in so doing 
was that, by such a plan, he was enabled to keep a uniform feed on the 
mill, by sizing the wheat on the first break. The writer does not believe 
that this result would be accomplished in this way; and, in the second 
place, does not think it desirable to try to do it. The uniformity of the 
feed on the second break machines would be dependent upon the uni¬ 
formity of the grinding upon the first, and it is not desirable that the 
grinding should be uniform on the first break. Certain conditions 
of the wheat demand closer grinding, and certain other conditions de¬ 
mand relatively higher grinding. To make the grinding on the first 
break conform to the set of the feed gates on the second break rolls, is 
going out of the way to accomplish something that is not desirable even 
if it were attainable. One does not want a uniform feed on the mill. 
There are certain times when it should be relatively light, and certain 
other times when it should be heavier. For instance, with soft wheat it 
may be desirable to run a light feed and with hard wheat a heavy one. 
The tail end of the mill will prompt as quickly as anything in this 
matter. 

This miller said that closer grinding on the first break would naturally 
reduce the feed on the second, and consequently demand that feed be 
taken off the first break machines, and in this way compensate for the 
effects desired, because of hard or soft wheat. With this view of the 
case it is presumed that the low grinding on the first break, because of 
the wheat being soft, would reduce the feed on the mill enough to make 
the bolting all right because of the stock being softer; that is, the de¬ 
mand for low grinding at the head of the mill would cut down the feed 
enough to compensate for the demands of a light feed further on in the 
processes of separation. But this sounds and looks altogether too nice 
to work out. It is these acute, elegant ideas that are liable to lead peo¬ 
ple astray. There would be more frequent changes undei these cir- 
cumstances on the first break, and less ladical changes of the teed on 
the breaks following the second. 1 he closeness ot the grinding, as said 
before, would make a lighter feed all the way through, and as such 


i74 


GRADUAL REDUCTION .Mil,I,INC. 


grinding would be demanded on the first break by soft wheat, this 
diminution of the volume of stock would presumably make relatively 
closer grinding where least desired with this kind of wheat; that is, on 
the breaks following the second. On the whole, it does not appear 
profitable to follow arbitrary rules in regard to these matters. 




CHAPTER XXIX. 


THE THIRD BREAK-CORRUGATIONS FOR THE THIRD BREAK-THIRD BR 

SCALPER FOURTH BREAK CORRUGATIONS — SCALPING REEL 

FOURTH BREAK-FIFTH BREAK-CORRUGATIONS-QUALITY OF 

FIFTH REDUCTION STOCK-FIFTH REDUCTION MIDDLINGS. 


EAK 

FOR 

THE 


The third break stock is the summit of excellence of the break stocks. 
The descent in quality is both ways from this break—to the first on one 
hand and the sixth on the other. The use of this pyramidal form of 
illustration is all right as applied to the third break, but if it could be 
construed to mean uniformity as to the first and sixth, it would be in¬ 
correct. The first break is not so good as the sixth; the second is bet¬ 
ter than the fifth and not so good as die fourth. Thus the ascent is not 
uniform in both directions, either numerically or in quality. 

The stock from this break is the brightest and cleanest of any, and 
the most should be made of it. It is fair to say that the first and second 
breaks are preparatory to the third and fourth; but, as far as that goes, 
each break should be preparatory to the next, and the sixth, or last, to 
the feed pile. It is well to consider what follows in setting the breaks, 
and there is this fortunate circumstance, that when one is thus looking 
ahead, he is doing the best possible thing for the work immediately in 
hand. For example, when one is setting the second break rolls, he has 
in mind the quality of stock desirable for the third and subsequent 
breaks, and, in so doing, the product of the second break is benefited 
by this intelligent foresight. 

Mention has been made that with soft wheat closer grinding is re¬ 
quired on the first and second breaks, than with hard. This is for the 
purpose of getting the work of reduction sufficiently advanced so that 
the grinding on the third and fourth breaks may be more open. Close 
grinding on these middle breaks with soft wheat means soft flour and 
flat, soft middlings, which are difficult to purify, and, at the same time, 
the bran is left in such a condition that it leads to unnecessarily impure 
stock on the fifth and sixth breaks, and bran which it is difficult to clean. 
If one were to grind as close on the first and second breaks with hard 


176 


GRADUAL REDUCTION MILLING. 


wheat as he does with soft, the stock would be too much cut up when 
it reached the fourth break. Such a condition of things would suggest 
a more uniform grinding with this class of wheat. A good general rule 
in regard to the breaks would be to so grind as to keep the stock in as 
large pieces as possible for the next break. This idea, well followed up, 
would work out its own methods, and, approximately, those just enum¬ 
erated. 

The corrugations for the third break are usually cut fourteen to the 
inch; sometimes twelve, but not commonly so. The question of round 
or sharp corrugations is one which will settle itself if it is ever settled. 
The difference in merit as to the different corrugations is not so great 
but that all are being operated successfully—that is, they are making 
money—and every miller appears to be satisfied with the roll which he 
is handling. If asked squarely which form of corrugation was the best, 
the writer would say the one which makes the largest proportion of mid¬ 
dlings and leaves them in a condition to be most readily purified, and 
at the same time yields the best quality of break flour. If asked which 
corrugation would meet this idea, the writer would say he did not know, 
as there are very many different forms made and operated under many 
different circumstances, and a positive opinion on such a basis would 
not be entitled to respect. This is a question which will settle itself 
when there is any need for its being settled. 

The speed of corrugated rolls is a good deal talked about, and might as 
well be mentioned in connection with the third break, as any place. It 
would sound very well to say that rolls should run slower operating on hard 
wheat than on soft wheat. At first glance this might appear to be true 
and to be sustained by results, but the fact is that the evils of running 
rolls too fast are not so apparent on soft wheat as on hard. But they 
exist just the same, and if a high speed is wrong on hard wheat, it is 
wrong on soft. It is supposed that we are working to get the best re¬ 
sults; that is, to get the most money out of the wheat. Where the re¬ 
sult of a wrong is distinctly apparent, the fact of its being less apparent 
under other circumstances does not imply that a wrong does not exist. 
T his view of the case is brought to mind by a spring wheat miller, who 
said, while we were looking at a set of rolls which were running very 
fast: “If those rolls were running on spring wheat, they would knock 
the wheat all to pieces, bran and all,” and then as he talked about it he 
suggested that the evil was only one of degree when applied to the soft 



GRADUAL REDUCTION MILLING. 


177 


wheat on which they were running. The general impression is that 225 
to 250 revolutions per minute is about right. 

The question of differential motion on breaks would be as endless as 
the former discussion as to the speed and dress of millstones, and will 
not be entered into at this time. 

The scalping reel following the third break for a 400 or 500-barrel 
mill should be twelve feet long, and for from 100 to 200 barrels, about 
six feet long. A fourteen corrugation on third break stock would re¬ 
quire No. 22 wire as the proper clothing for this reel. 

Tne fourth break stands up well with the third. It is rather specky, 
is softer, the granules are smaller, and the volume of stock some¬ 
what less. More harm can be done by poor grinding on the fourth, 
fifth and sixth breaks than on the first, second and third. It is because 
the proportion of deleterious material is larger as the tail end of the 
breaks is reached, and then again, the bran which has been subjected to 
the severity of the previous reduction machinery, begins to break up 
and pulverize. The legitimate end in milling is to make good Hour and 
clean feed. These two things have to be kept in mind at every step, 
counting from' the first break down. In order to make clean Hour on 
the fourth and fifth breaks, one wants to touch pretty light on the stock, 
and, on the other hand, we want clean feed. Allowing that this is so, 
it will naturally suggest that we should grind as close as possible so as 
not to injure the stock as to its quality or size, on the first two breaks. 
This statement would bring about the old talk about the different ways 
of grinding hard and soft wheat. Any grinding which implies bruising 
or mashing is improper or wrong. It means pulverized bran, flaky mid¬ 
dlings, and soft flour. All this is dependent upon the extent to which 
the evil is followed. It is a question of degree. This matter of degree 
is the sum and substance of milling results; it is the degree of purity or 
impurity in flour. There can be no absolutely pure or impure stock in 
the mill. The word clean, as applied to flour and feed, is in the same 
position. They have to be used in a licensed and unsatisfactory way. 

The fourth break rolls, as a matter of fact, require more grinding sur¬ 
face than any of the other breaks, but usually have the same amount 
as the third, wh ch is about as near as one can get to the desired result 
in actual practice. The reason this extra amount of grinding surface is 
required is that there are a larger number of pieces than before, without 
a corresponding reduction in the bulk of the pieces. 

(12) 


1 7 8 


GRADUAL REDUCTION MILLING. 


The corrugation for the fourth break is usually sixteen or eighteen to 
the inch—sixteen, probably, more often than eighteen at this time. 
There appears to be a growing favor for coarse corrugations on winter 
wheat, however it may be for spring wheat. 

The scalping reel for the fourth break should be clothed with No. 24 
wire or its equivalent in grits gauze. Grits gauze, by the way, lasts very 
well on the fourth break. The other breaks will cut it out too rapidly 
to justify the expense. The length of the scalping reel for this break 
oh a 400 or 500-barrel mill would be thirteen or fourteen feet. 

It is a common thing in many mills not to open the first three breaks 
when shutting down the mill, but merely to cut down the feed. 

From the fourth break scalper there is the natural drop to the fifth 
break, and it is a drop in the sense of a descent from one elevation to 
another, and also from a higher quality to a lower. At the best this 
fifth break stock is questionable in quality, and more particularly as to 
the quality of the middlings. Where one is running the four m'ddle 
breaks together—the second, third, fourth and fifth—if he will take the 
fifth break out, he will notice a wonderful difference in the quality of the 
middlings. It will show with all the middlings which pass through a No. 
4 cloth, or finer. Whereas, it might have contained fine, fibrous, red 
stock in case of the fifth break middlings being run in, it will show much 
cleaner with them left out. There is quite a quantity of coarser stock 
which goes in with the coarse middlings with this break, but there can¬ 
not be any considerable quantity of coarse middlings; in fact, the quan¬ 
tity must necessarily be very small, owing to the thickness of the stock 
before it is reduced, and its generally depleted condition. However, 
there is quite an amount of stock which will go through coarse cloth. 
It is bran with a small amount of adhering middlings. Altogether this 
substance is more like tailings, and should be treated as such. It is not 
an easy matter to get the fifth break fine middlings in a condition which 
will justify its reduction into patent Hour. But they will make a most 
excellent quality of clear or bakers’, if reduced on smooth rolls. What¬ 
ever may be said about the middlings from this break, the Hour belongs, 
beyond question, with the clear; that is, the Hour made during this re¬ 
duction. It is relatively of a better quality than the middlings. The qual¬ 
ity of the stock going to the fifth break machines—its size, texture and 
general appearance—is an indication of the care and skill given in grind¬ 
ing on the previous breaks. It is here that previous good or bad work 


GRADUAL REDUCTION MILLING. 


179 


shows itself the plainest, and it exerts a marked influence on the quality 
of the product of this reduction. If it comes to these machines in bad 
order, no work, however skillful, can redeem it. 

Twenty corrugations to the inch seems to be the accepted cut for roils 
for this break. No. 26 wire or the corresponding size of grits gauze is 
used for the scalpers. Thirteen or fourteen feet is a good length for a 
300 or 400-barrel mill, and, for the reason previous’y stated, about half 
that length would do for a mill of from 100 to 200 barrels. Compari¬ 
sons are often made for a 400 or 500-barrel mill similar to the above. 
This does not imply that this work is done for 500-barrel millers, but 
rather for the purpose of comparison and proportion. One has to take 
something for a basis in order to work both ways. There are a great 
many more mills which are smaller than this than there are of this size 
and larger. In fact, the writer judges that the number is so much greater, 
that the aggregate output from them would be immensely larger. 

A very successful millbuilder told the writer that all four-break mills 
should have five breaks. He said that in all mills where they placed a 
four-break combination machine, they sent the tail of the last scalper to 
a single pair of rolls to clean the bran. It is customary to speak of all 
reductions by corrugated rolls as breaks. In a six-break mill the first 
four reductions are, in practice, breaks; the fifth and sixth, cleaning re¬ 
ductions. They scrape the bran, however. The writer has no disposi¬ 
tion to complicate the general expressions or nomenclature of milling 
operations by inviting a distinction in the naming of these reductions. 

There is a general disposition to separate the fifth break stock from 
the usual stream of material from the middle breaks. While it has been 
the custom to run the products of the second, third, fourth and fifth 
breaks together, and bolt out the stock as though it were one product, 
there is a disposition to draw out this fifth break stock and bolt it by 
itself. The Hour is nice and bright, but the middlings do not belong 
with those from the second, third and fourth reductions. They are red, 
fibrous, and generally irredeemably bad. Their condition may be im¬ 
proved, but the purification cannot be effected to such an extent as to 
make a desirable proportion of middlings suitable for patent flour. This 
may be proved by undertaking to purify these middlings by themselves. 
To be sure there will be a small proportion which is all right, but there 
s shown to be such a large amount of bad material that the evil of run¬ 
ning this stock into the best flour in the mill cannot but be seen. All 


i8o 


GRADUAL REDUCTION MILLING. 


this applies with greater force to winter than it does to spring wheat 
milling, though it may be considered as applicable in principle to the 
latter. It may be said that the taking out of this fifth break stock from 
the body of the mill from the stream of products from the three pre¬ 
vious breaks will reduce the proportion of patent Hour. Not so; it will 
reduce the bulk of stock going to the purifiers, and the bulk of purified 
middlings may be slightly reduced; but the perfection of their cleaning 
will be more apparent, and when it comes to their reduction into flour, 
it will be found that as much or more flour will be taken from the reels 
where the middlings are bright and clean than where they are less bright 
and clean. If these middlings were absolutely pure—something which 
never happens—they might be reduced so that their whole bulk would 
go into flour. As it became apparent that the middlings were less clean, 
it would be found that the proportion of loss would be much greater 
than the proportion of stock which went to make these middlings un¬ 
clean. To illustrate this in another way: Say we have 99 pounds of 
absolutely pure middlings—middlings which might in theory make 99 
pounds of absolutely pure flour—and say that some person would drop 
one pound of finely pulverized bran into the mass. Now, our reduction 
and separating machinery is not so perfect that it will take this 99 pounds 
of stock and separate therefrom the one pound of impurities. We 
know that a large proportion of stock would have to be taken out in 
order to get rid of the impure material, and even then we would find 
traces of impurities running through the reduced material. The pres¬ 
ence of impurities suggests the necessity of large waste in order to get 
rid of these impurities. The nearer we can come to cleaning the bran 
material previous to the reduction of milling stock, the less is the waste. 
Thus, by keeping out the fifth break middlings from the body of other 
middlings, the proportion of waste is less; and, while the bulk of mid¬ 
dlings may not be so large where this stock is omitted, it will be cleaner, 
and for that reason the yield of patent flour from the wheat will be 
larger. 

Merely because the fifth break middlings are not run into the body of 
other middlings, there is no reason why they should not go onto the 
purifiers. Enough benefit may be derived from this stock to justify the 
expenditure in extra spouting and elevators, and, if need be, extra puri¬ 
fiers. 1 he need of extra purifiers is spoken of in this questioning way 
because it is not always necessary to buy them new. In quite a num- 





GRADUAL REDUCTION MILLING. l8l 

ber of mills which are large enough to justify this division of stock, it 
will be found the middlings can be made much cleaner, after taking out 
the fifth break stock, with one or two less machines, than they could be¬ 
fore with full equipment on one general classification of stock. Most 
of the middlings from the fifth break which one would care to run into 
a purifier will pass through a No. 4 cloth, and, as the wheat is harder, it 
will be found that there will be an increasing proportion of these mid¬ 
dlings which will be suitable for running in after purification, with the 
other stock, and for the reason that these middlings are fine, there need 
be but one grade of these middlings to be purified. 

The amount of middlings from the fifth break is usually overestimated. 
The stream of stock is quite large, but it is mostly made up of fine bran 
and fibrous matter. One can prove this to his satisfaction by taking 
some stock from the fifth break and sifting it. The large proportion of 
fine bran and the small proportion of real middlings will then be made 
apparent. It would be drawing it a degree too fine to suggest that the 
fifth break flour be bolted separately. All that is absolutely necessary 
in the separation of fifth break middlings is to run the product of the 
fifth break scalper into a separate middlings scalper clothed with, say, a 
No. 9 cloth. Then the product of this No. 9 cloth should be run into 
break Hour reels. 


CHAPTER XXX. 


THE FIFTH FREAK—NUMBER OF BREAKS FOR A GRADUAL REDUCTION MILL, 

SEVEN BREAKS-SMOOTH ROLLS FOR ONE OF THE LAST BREAKS-THE 

SIXTH BREAK-SIXTH BREAK SCALPER-SIXTH BREAK FLOUR-BREAD 

FROM SIXTH BREAK FLOUR-SIXTH BREAK FLOUR SHOULD BE RUN BY 

ITSELF. 

According to the original plan, it might be in order to drop the breaks 
at this point, and take the products of the four middle reductions and 
dispose of them, but while we are about it, we wi.l go on and finish up 
what might be said about the sixth. 

Six reductions by corrugated rolls is the smallest number possible, 
where good work all around is desired. Of course there are many rea¬ 
sons why less are used, and it is desirable that study and attention be 
given to mills with a smaller number of reductions. They are a neces¬ 
sity, and do better work than was done by the old system. As far as 
quality of flour goes, it is possible to make as good flour on a small 
mill as on a large one, but when one comes to do this in this way, it has 
to be done at so large a cost—at such an expense of stock—it is a dead 
loss. There must be a great deal of good and poor stock together 
thrown away in order to bring about such a result. Such milling would 
not be entitled to business consideration. The mills with three and 
four reductions, as they are now built, are better than they were some 
time ago. The rage for large mills having been largely satisfied, those 
engaged in building mills are giving this question of small mills their 
attention; but they cannot be made to compete with the more fully 
equipped organization, and, while such mills are being built, he who 
plans or arranges them should have in mind the addition of a sufficient 
number of breaks to make the mill complete. When one considers the 
difficulties of making clean flour, sharp middlings, and clean bran with 
six reductions, and more especially on soft wheat, it would seem rather 
hard to cut this number down to four. Something would have to be 
sacrificed. It would be the yield—the flour or the middlings—and at 
certain times it would necessarily have to include them i ll. 'There are 


GRADUAL REDUCTION MILLING. 183 

few millers who have not wished for a seventh break, which is certainly 
a move in the right direction. Seven breaks are used in a number of 
instances. If six breaks are necessary on spring wheat, as they cer¬ 
tainly are, seven breaks are equally necessary for winter wheat. 

The writer does not wish to have his statements construed into crying 
down the three and four break mills. They are a commercial necessity 
in the places where they are built, and, in a place where a stone mill 
will keep its head above water, they will make money. On the other 
hand, the owner of such a mill should remember that a larger number of 
breaks will do still better, and at the same time do not increase the cost 
of the mill in the proportion a first thought would suggest. The same 
shafting would probably do for a six-break mill, a couple of elevators 
and scalpers; and the additional belting and spouting would about tell 
the story, counting in, of course, a double set of rolls. 

Some time since, in considering the finishing of the bran, mention 
was made of the possibility of doing a good work with smooth rolls, 
using a smooth roll reduction after the fifth, and following it with the 
corrugated reduction, which would be a seventh reduction. This smooth 
roll reduction would be followed by a dismembrator. The general pur¬ 
pose of this method would be to get a whiter flour from this stock than 
could be done by corrugated rolls. There would be no middlings. The 
tendency of the pressure of the smooth rolls would be to pulverize the 
flour stock remaining on the bran, though it would not detach it. 1 he 
action of a dismembrator or disintegrator, or something of this kind, 
would dislodge the Hour particles and complete the work of the smooth 
roll reduction. This stock could be scalped by the dismembrator or 
separately. The Hour from such a process would be much whiter and 
cleaner than by the ordinary sixth reduction method. The bran would 
not be so well cleaned, but there would be a certain proportion of good 
material separated which would not otherwise be sccuicd. 1 lus idea 
was suggested by some work of smooth rolls in reducing wheat. Each 
reduction was followed by a dismembrator, the flour was of excellent 
quality, and the middlings surprisingly bright and round. This was a 
system where all the work was done on smooth rolls, excepting, per¬ 
haps, the first, which was closely corrugated. It comprised four breaks, 
and the bran was quite clean; in fact, the finish was as good as from 
many four-break mills. It is strange that we have not heard more of 
the results of this plan, as the showing was good, and it appeared to 


184 


GRADUAL REDUCTION MILLING. 

have considerable push behind it on the start. One thing it did show 
v’ery clearly, was that it was possible to get much better Hour from bran 
stock than by more severe methods of reduction. It is clear enough 
on the face of it that smooth rolls will get a better quality, though not 
so large a quantity, of Hour from this kind of stock than sharply corru¬ 
gated rolls. To make up the matter of quantity we have the dismem- 
brator, and following its action the seventh reduction, or corrugated rolls. 
'These rolls would be dressed and arranged otherwise the same as for the 
sixth reduction by the ordinary method. Here we have an equipment 
which, taken altogether, would get more dour of better quality out of 
the wheat—which means more money—than the ordinary arrangement. 
The seventh, or last reduction, would find the stock in good condition 
to clean. 

Mills which are arranged on the basis of three, four, or even five re¬ 
ductions, are necessarily temporary as far as that number of reductions 
is concerned, and this should be kept in mind in planning a mill. The 
same cause which led to the change from millstones to rolls in the first 
place, will inevitably and certainly cause us to finish out the line of 
breaks. After the change from millstones to rolls has apparently been 
made, taking the whole country together, there is going to be a big busi¬ 
ness for millfurnishers in finishing up mills; that is, doing over again and 
adding to, work that was improperly or incompletely done. There are 
twenty mills incomplete in many respects where there is one which has 
enough machinery in it for the quantity of work it has to do. The greatest 
deficiencies are in small mills, where they are short of capacity, head 
and tail, and all the way through. The corrugated rolls are .crowded 
and there are not enough smooth rolls; the number of reels is limited, 
and the purifiers are wonderfully overworked, both as to volume and 
quantity of stock; and, as said before, there is going to be a large busi¬ 
ness straightening this out. The necessity for this work is as clear and 
inevitable as was that of the original change. 

'To take the sixth reduction as it naturally follows the fifth, there comes 
to mind a time when thirty corrugations to the inch was almost uni¬ 
versally used for this break, but it did not take people long to find out 
that this was too fi e; they would do all right until they began to wear, 
and then the trouble would begiiL After this was noticed, the change to 
twenty-four corrugations was made, and now that number is almost uni¬ 
versal. To get the best work out of bran rolls, the stock should go to 







GRADUAL REDUCTION MILLING. 


185 

them broad and most thoroughly dusted. It is easier to get broad, 
finished bran from rolls while they are new than after they have been 
run for some time. This is because, in the former instance, the rolls do 
not have to run so close. 

Sixth break rolls are usually run somewhat faster than some of the 
other breaks. This is done to gain capacity, as the necessity of the 
case demands that this break should have as much, or more, grinding 
capacity than any other break. This is on account of the spongy char¬ 
acter ot the stock as it goes to the machine, and the way in which it 
feeds. 

A good scalper for this break is a common form of centrifugal reel, 
with the reel stationary, and spiders with steel blades running at about 
350 revolutions per minute. The spiral should be about one-sixth. 
These reels are ordinarily made in halves, with the top to come off. As 
the reel does not revolve, it is not necessary to clothe the extreme top 
of it, but it should be closed with tin or zinc. The wire is put on from 
the inside of the reel. It being in halves, it will be readily seen that 
this is a very simple process. The longitudinal ribs are seven-eighths 
thick and about eight inches on centre, and those which run around the 
reel are the same thickness and five inches on centre. A good way to 
put wire cloth on such a reel is to first cover it with coarse cloth, four 
meshes to the inch, securing with two-pointed tacks or small staples. This 
forms a solid groundwork on which to place the finer wire. A reel of 
this kind seven feet long will take off the bran from a 500-barrel mill 
and whip it out so clean that there will be no work for a bran duster. 
For this break this reel should be clothed with No. 30 wire. 

There is another mistake sometimes made which is worthy of consid¬ 
eration, and that is the running of sixth break flour in with the low 
grade. This flour is far superior to that made from the red dog. It 
shows better under the spatula, works better in the dough, and is better. 
It will bring in more money. It makes toothsome, nutritious bread, 
and any miller who will take the pains to take out a little of this flour 
and bake it, can easily convince himself that he is doing a wrong thing 
when he runs this product in with the low grade. 1 he bread will be 
about the color of light manilla paper, but it comes nearer having a 
positively attractive taste without the use of butter, than any other. 
The reason for this bread being so nutritious and pleasant to the taste, 
may be found in the fact that the larger proportion of gluten sacs or 


i86 


GRADUAL REDUCTION MILLING. 

cells are found next to the bran. The scraping off of this part of the 
wheat by the sixth reduction rolls, is the explanation of the excellence 
of this flour. The analyses of the products of C. A. Pillsbury & Co.’s 
mill by Mr. Richardson, of the United States agricultural department, 
show the correctness of this theory, in that the sixth reduction chop 
proves to have the largest proportion of albuminoids or nutritious mat¬ 
ter. According to the analyses, there is an increase from the second to 
the sixth, the second break containing the smallest proportion of 
albuminoids and the sixth the largest. The first chop contains a larger 
proportion than the second, on account of the germ which it contains. 
The first break flour would be found to have a smaller proportion of 
the albuminoids than the other breaks, though the chop which contains 
the germ may be shown to have a larger proportion than the second. 
The writer would not run the sixth break flour in with any other. If 
sold by itself it makes a good XXX St. Louis grade. 




CHAPTER XXXI. 


DUST MIDDLINGS-DUST MIDDLINGS FROM HARD AND SOFT WHEAT— 

PURIFICATION OF DUST MIDDLINGS-THE CUT-OFF FROM THE FREAK 

FLOUR REELS-RETURNS. 


The product of the four middle breaks contains all of the high grade 
flour there is in the mill, and of course a part of the low grade, which 
is taken out by the various separating devices; that is, that part of it 
which is recognized as low grade flour, because of its going into the low 
grade packer. If one were inclined to be too particular or annoyingly 
exact, he might say theie is always a certain proportion of low grade 
stock which gets into high grade flour, and certain high grade flour into 
low grade slock. But this would be carrying out in a detailed way the 
statement that milling methods are not and cannot be perfect. The 
first thing usually done with the break chop is to remove the middlings 
by dusting the flour out of them. Sometimes this is done by first tak¬ 
ing out the coarse middlings, and next the finer. But this can be done 

at one operation, and at the same 
coa rse mips time they can be graded into two 
fihe mios grades. According to the experi¬ 
ence of the writer, the dusting can 
be more effectually done by keeping 
the coarse middlings in with the 
fine while they are being dusted, but 


BREAK 

9 

A. 

STOCK 




if—- ■< - 


W 12 

13 

'' 

f 

--*-- ' 

. - 


1 n /4 

_ 'll 


DUST 


M,DS * not after it is desirable to take out 
flour. Fine middlings from soft wheat can be well dusted in this way 
where it is next to impossible to do it in any other way, excepting by 
the expenditure of a large amount of bolting capacity, which might be 
profitably used for other purposes. It may not be necessary to do this 
with hard wheat, but even under such circumstances the dusting can be 
done on less surface by this method than otherwise. It might be sug¬ 
gested that the coarse middlings would beat the red stock through into 
the flour stock and fine middlings. It could not ha\e this effect with 
the fine middlings to any greater extent by this method than by any 




























GRADUAL REDUCTION MILLING. 


188 


other, and in case of the hour, there is away out of the difficulty, which 
would work well in connection with any system of scalping, it is illus¬ 
trated by the accompanying sketch. 

Whenever the miller notices that the hour stock coming from the tail, 
or near the tail, of the No. 9 cloth, is red, or contains too large a pro 
portion of impurities, he can throw such stock into the bottom conveyor 
by drawing slides, and from there to the bottom reel, where it will be 
bolted on finer cloth than it would be if it went into the first flour reel, 
as will be noticed in the diagram. The cut-off from the first hour reel 
also goes into the second reel with this stock; thus both meet the re¬ 
quisite cloth numbers to make cleaner flour. The Hour from the second 
reel can be improved by throwing in softer stock from the first. 

A method which is not at all uncommon is to take out the coarse 
middlings through the flouring reels, and finally tail it over the last; if 
not over a Hour cloth on this reel, over a piece of slightly coarser cloth 
placed on the tail end of it. A still more common way is, after taking 
out the coarse middlings, to run the fine middlings through the flouring 
reel and tail off over a fine middlings cloth at the tail, say No. 9. The 
objections to such a method, which are quite grave, were outlined in a 
previous chapter when considering, in a detached way, some points in 
regard to scalping. It is not necessary to go over this here. It is suffi¬ 
cient to say that the idea was to dust the coarse and fine middlings to¬ 
gether for the purpose of getting all the tlour out of the latter, and at 
the same time to keep the hour stock as soft as possible by keeping the 
fine middlings out of it. The purpose of keeping the Hour stock soft 
is to make the flour cleaner. The methods just outlined, and to which 
objection was made, do neither of the things which are here mentioned 
as desirable; that is, it keeps the flour stock sharp enough to injure the 
flour coming therefrom and still not sharp enough to dust the fine mid¬ 
dlings. A little examination of the diagram here given will show how 
these objections are met, even where the plan of throwing the more 
impure stock, which comes through the No. 9 cloth, into the bottom reel 
is not resorted to. The tail of the last reel is called dust middlings, and 
will invite detailed attention. 

But before doing this, the idea suggests itself of considering the plan 
of treating the stock from the fifth break by itself, in the separation of 
the flour therefrom. This would bring the second, third and fourth to¬ 
gether, and, as implied, the fifth by itself. The reasons for doing this, as 



GRADUAL REDUCTION MILLING. 


189 


formerly named, are that the middlings from this break injure the mid¬ 
dlings stock from the three breaks mentioned, and make the process of 
purification unnecessary, elaborate and complicated. The necessary 
thing to do in bringing about this result, is to have a separate middlings 
scalper for the stock from the fifth break. This is illustrated by the 

diagram here presented. The 
product of that scalper is shown 
as going in with the stock to the 
bottom of the reel; that is, it is 
arranged so that it may all be 
sent there, though it is possible 
that there may be times when it 
will be desirable to send a part 
into the upper reel. It should be 
remembered that the flour from 
the fifth break is not relatively of 
so low a grade as are the mid¬ 
dlings. The tail of the fifth break scalper is supplied with a grading and 
scalping cloth, so that a part of the product of the fifth break stock 
scalper can be sent directly to the tailings rolls. The grading cloth sug¬ 
gests that the middlings be run into two grades. It would depend 
upon the size of the mill, as to whether it would be desirable to do this. 
If not, this grading cloth could be omitted, and the middlings run to 
a distinct set of purifiers. Where the middlings are divided into two 
grades, it would imply that one or two extra machines should be used. 
A part of the purified middlings from this break would be good enough 
in quality to run in with those used in making the patent Hour. The 
fact that all these middlings are not adjudged good enough for patent 
Hour does not imply that a part may not be used for that purpose, and, 
furthermore, it does not suggest that the discarded portion should be run 
in with the tailings, or other stock of similar grade. There is an inter¬ 
mediate grade between purified middlings and tailings, and it is here 
this stock belongs. 

















CHAPTER XXXII. 


PRODUCT OF THE FOUR MIDDLE BREAKS-SCALPING OF THE MIDDLE 


BREAK STOCK-GRADING THE MIDDLINGS-CLOTHING OF THE BREAK 


FLOUR REELS-A METHOD OF SEPARATING THE FIFTH BREAK MID¬ 

DLINGS. 


The last chapter closed with an allusion to dust middlings. The dia¬ 


gram or illustration which was given in connection therewith is here re¬ 
peated, in order to define what is meant by dust middlings. The nam¬ 
ing of stocks is so mixed and uncertain that explanation at some length 
is often necessary in order to make oneself understood. 


It will be noticed that what is here named dust middlings is that class 


of stock which will pass through the No. 9 cloth above, but not through 
the flour cloth below, being too fine to be treated in the regular way 
with the other middlings, and too coarse for flour. Efforts are made to 


brow, n — -1—7—n purify this class of stock in the reg- 


BREAK 


STOCK 


coarse mips u } ar wa y py t ] le purifiers. Accord- 


! >- F , HE mios~ ing to the present understanding of 


2_[] the case, very little is gained by such 


means. The stock may be a little 



purer, but, as an offset, the waste is 
to be considered in estimating the 


to be considered in estimating the 
value of the purification. The dif- 




—vw—» m,Dj value of the purification. The dif¬ 


ference in specific gravity between the stock and the contained impuri¬ 


ties is so slight that as yet we are deficient in the mechanical means of 
making such a separation by means of air currents or sieves. The 
writer does not mean to say that the purity of this stock will not be 
affected by the action of the purifiers in the regular way, but questions 
the profit of such a process. Mechanically it might work reasonably 
well; viewed from a business standpoint it will bear investigation. The 
writer is aware that the dust collectors keep the stock from the fans in¬ 
side the mill; and also that the tailings and cut-off from the machines 
handling this stock are controllable in the direction of its travel. But 
if special means be used in disposing of this stock, or of that from the 






























GRADUAL REDUCTION MILLING. 


igi 

dust collectois of the same machines, there is the additional complica¬ 
tion and expense of plant, which cannot be undertaken except in a few 
cases, and that when the output is large and means abundant. And 
again, accepting all these arrangements as possibilities, the stock to be 
so handled would not be very much different from the original middlings 
going to these machines, and the middlings would not be greatly im¬ 
proved. Thus, in any event, the result of such a system could not be 
largely benefited. 

With soft wheat this grade of stock is quite bright, if not contami¬ 
nated with other material running in with it from other directions than 
from the stock from which it is supposed to be originally taken. In 
some instances, where it is desirable to submit this material to purifying 
action, it is run through a centrifugal reel before such handling; that is, 
by the purifiers. 

The best purifier for the dust middlings is the smooth roll and the 
following reel or reels. This Hour stock is reduced and the bran specks 
and other impurities are not greatly disturbed. This stock should not 
be ground too close, as by this means the impurities are pulverized and 
the 'floury particles battened in such a way as to go off with the impur¬ 
ities. There can be no reason for a close grinding in this material. 
There will be more Hour taken from the reel when the grinding is prop¬ 
erly done than when it is ground close. What is wanted is to break up 
the floury particles without submitting anything to a pulverizing action. 
Aside from the other damage which close grinding does, it makes it dif¬ 
ficult to finish up this grade of stock on the subsequent reductions. By 
that is meant it becomes soft and feathery, and is partially insensible to 
the action of the following roller reductions. It passes through the 
rolls without being disturbed, and one reduction merely calls for another, 
until the tail end of the mill is reached, and even then there is stock 
going into the red-dog from this source which does not belong there. 
It is not there through deficiencies in the process, but from lack of the 
proper manipulation of the means at hand. By the most careful and 
intelligent grinding this will happen in a less degree. It will become 
somewhat soft, and, as expressed before, somewhat feathery. The intro¬ 
duction of the centrifugal reel in the separation of the second reduc¬ 
tion of this grade of material would not be out of place. If there be a 
third reduction, as there should be, there should be a centrifugal reel 
there also. Three reductions of this material where the feed is not too 


I92 GRADUAL REDUCTION MILLING. 

heavy and the grinding neither too close nor too open, will prepare what 
remains for the red-dog. 

The dour from the first reduction of the dust middlings will he next 
to the patent dour in quality. When one finds this dour specky and 
gray, it may be from two causes other than the character of the original 
stock. It may be from too high or too low grinding. The cut-off or 
the tail will show which is wrong, without going to the product before it 
goes into the reel, which it is not always convenient to do from the 
point where the dour is discharged. It is not always necessary to change 
slides to remedy defects in the quality of the products of dour or other 
stock. More often when there is not a change in the feed or the texture 
of the stock, a change in the reduction will bring about the desired end. 

The cut-off from the last break chop reel remains to be considered. 
There was a time in the history of stone milling, and in fact it was all 
the time previous to the last few years of the existence of that system, 
when this or corresponding stock was called returns. To quote an old 
phrase, “it went back to the head of the chest.” The setting aside of 
this system of returning marked an epoch of decided improvement. It 
added greatly to the purity of the dour. It was an old habit, one almost 
as old as milling itself, and it was hard work getting out of it. It was 
not alone the cut-ofi' from the chop which was sent back as returns, but 
the cut-ofi' from nearly everything in the mill, as well as dustings from 
middlings and other questionable material. As a matter of fact, if the 
miller of those times did not know what else to do with certain stocks, 
he spouted them into the chop elevator and lus mind rested easy. If 
the same system had been carried on in the purification of his own blood 
or its manufacture, he would have been a dead man inside of forty-eight 
hours. The organizer of the human system of purification did not adopt 
the system of returns, but his creatures introduce it into their anatomy 
when they drink water contaminated with their own offal by means of 
cesspools and sewerage, and in other instances by oreathing the air from 
water closets and sewers. This is taking back into the human system 
material which has once been discarded; it is a method of returns, and 
it kills through the medium of typhoid fever and other diseases. This 
system could not make itself so prominently felt in the manufacture of 
dour as it could upon the health of human beings, but when considered 
with reference to its relation to good milling, to the purity of the stock, 
it was pernicious in the extreme. It was undoing what was the avowed 


GRADUAL REDUCTION MILLING. 


r 9 3 

purpose of milling methods to do. It was taking out poor stock and 
then putting it back again. It was an attempt at purification. It re¬ 
moved a part of the impurities from one body of material and dumped 
it into the same stock which followed. This system is still in existence 
in a mild way in the diagrams which are published from time to time, 
but it exists only in the lower grades of stocks, and does not affect 
the flour which is taken out earlier in the process. 

This cut-off is stock which comes for the most part through a No. 14 
cloth. It is flour which is too gray or impure to go into the packers. It 
is larger grained than some of the Hour which goes through a coarser 
cloth above. This is because of the stocks toward the tail end of this 
reel being sharp, and containing only a small proportion of fine flour. 
Thus it drives its way through the cloth. In many instances it is com¬ 
mon to run this material in with the dust middlings, and thus reduce it 
there. The objections to this method are, in the first place, that it makes 
this stock soft and difficult to feed on the rolls, which is a very serious 
matter. In the second place, though not second in importance, it is re¬ 
ducing stock which has already been through a flour cloth. This is un¬ 
necessary and need not be done. It accomplishes nothing. This stock 
maybe spouted in with the reduced stock from the dust middlings rolls, 
and thus go into the reels following to be rebolted. Where there are 
more than two reductions of this stock it would be better to send it in 
with the reduced material from the second reduction of the dust mid¬ 
dlings. No one who has not tried this method of separating this stock 
from the dust middlings before it goes to the rolls, can appreciate 
the difference which it makes in the feeding of those machines. It 
transforms the process of tending such rolls from an annoying, vexa¬ 
tious one to a comparatively simple and easy work. 1 here is no chok¬ 
ing off of the feed, consequently the rolls never “run dry” on this ac¬ 
count. When the soft stock is running into the hopper there is great 
temptation to raise the feed gate high, and let the stock all run into one 
end of the feed opening, and consequently through only a part of the 
reduction surface of the rolls, buch a condition of things not only does 
the stock very little good in the way ot reduction, but is injuiious to the 
machine itself. The importance of this matter of even, regular feeding 
on rolls cannot be overestimated. It not only has a decitled influence 
as to the capacity of the machine in reducing the stock, but its influence 
upon the quality of the flour coming from that roll is wonderfully marked. 

(*3l 


i 9 4 


GRADUAL REDUCTION MILLING. 

Take the stock when it is running through one end of the rolls as de¬ 
scribed, and then compare the result in Hour with that of a roll properly 
fed, and any one will say that there is a large difference in favor of the 
latter. 

To return again to the question of the cut-off: Its quality and sharp¬ 
ness will be dependent upon the amount of Hour taken off, together with 
the amount of Hour in the dust middlings, which is the tail of the last 
reel. The quality of Hour from the last reel should always be examined 
in conjunction with the cut-off from that reel. To look at it and see 
that it is satisfactory in color is not enough. One should know that the 
cut-off does not contain too much Hour, and that there is not stock in it 
which properly belongs with this reel. It is well to take all the Hour of 
proper quality which one can get at every opportunity, and not run stock 
over into the next reels with reference to the quality of that Hour. There 
are other means of regulating the quality there, which is by the grinding 
and the amount and kind of Hour cloth used. This thing of running 
clean stock from one reel into another when not necessary, gives the 
mill just that much more to do than it should. It is a false principle and 
poor economy. The cut-off from the last reel, when the slides are 
properly manipulated, is a good place to judge whether or not more or 
less feed should be put on the mill. If the Hour cloth is nearly all used, 
and the cut-off still soft, it is clear evidence that the mill has too much to 
do on the kind of stock which is being handled; or, on the other hand, 
if any considerable part of the reel is cut out, and this cut-off is still 
sharp, it is equally good evidence that the mill can have more feed. 
This is a general rule, and should be considered in conjunction with 
other stocks in the mill, rather than to be regarded literally and without 
further investigation. It might be that this part of the mill under cer¬ 
tain conditions, would indicate that heavier feed could be used, while at 
the tail end of the mill there would be difficulty in finishing up what 
it had. 


CHAPTER XXXIII. 


'i'HE PURIFICATION OF MIDDLINGS—DEVELOPMENT OF MIDDLINGS—DEFI¬ 
NITION OF MIDDLINGS-THE LIMIT IN PURIFICATION—MIDDLINGS PURI¬ 
FICATION AS A WHEAT CLEANING PROCESS-FINENESS OF MIDDLINGS 

WITH REFERENCE TO PURIFICATION-SIZING OF MIDDLINGS-SMOOTH 

ROLLS AS PURIFIERS. 

It was said in the first chapter of this book that the history of purifi¬ 
cation in general, without special reference to the purification of mid¬ 
dlings, would be the complete history of milling, and that an account of 
the methods of purification would commence with the cleaning of the 
wheat, and include a description of the various reductions and products, 
together with the separation and classification of the material on its way 
to the packer or feed bin. A comprehensive definition of milling would 
also be a definition of purification. Everything in a mill affects or is 
affected by the purifier. The purifier brought out the system of gradual 
reduction, which is a system of middlings making. When it was found 
possible to purify middlings, the thing to do was to make the largest 
quantity of them; hence the system of gradual reduction. Previous to 
this the best millstone work was developed by the purifier. It was the 
origin of all modern improvements in milling. The man who first de¬ 
veloped the idea of the purifier was the one who was the father of all of 
the recent milling ideas. Purification made pure flour possible. To 
develop this idea more clearly, it may be said that in order to have pure 
flour, there must be a pure something to commence with. As wheat 
could not be purified in its original form, other means had to be adopted, 
which developed the breaking of wheat for the purpose of purification. 
This is the only form in which wheat can be purified. Really, this is 
what the system of gradual reduction means—it is the breaking of wheat 
for purification—therefore it will be seen that the only form in which 
wheat can be purified is when it is in the form of middlings, and pure 
middlings means pure Hour. Purification is no,v the sum and substance 
of modern milling. Reduction is a detail, and, in so far as a system of 
reduction aids in the purification of the middlings, it is a good system. 


196 


GRADUAL REDUCTION MILLING. 


Anything connected with the reductions which betters the quality or 
quantity of the stock to be purified is so much in favor of that system of 
reduction. The benefits from a good reduction system will never be 
realized unless proportionately good purifying facilities are at hand. 

The term middlings has no special significance in the present system 
of milling, but in the old system, where only one reel was used, the mid¬ 
dlings was the middle product between the flour cloth and the ship stuff 
or shorts cloth; that is, it was the middle product. Thus it is probably 
fair to say that its middle position gave it the name of middlings. 

Middlings have been spoken of as broken pieces of wheat, and it has 
been mentioned that the purpose of so breaking the wheat has been 
with the idea of more perfectly, more completely cleaning it. To make 
the expression more forceful, it might be said that the purpose of milling 
was the cleaning and reducing the wheat. The first thing to be done in 
that line is by the ordinary wheat-cleaning machines, and then follows 
the breaking of it into particles with the view of separating the naturally 
deleterious portions, which impair the bread-making qualities of the 
wheat in a reduced condition. 

Having reached the limit in the cleaning or purification of the mid¬ 
dlings, their direct reduction into flour follows. This limitation is brought 
about in various mills by the ’amount of machinery contained therein. 
It is possible for some mills to go farther in the purification or cleaning 
of the wheat than it is for others, on account of one possessing a larger 
amount of machinery and a better system of arrangement. Another 
general limitation, and one that applies to all mills alike, is in the knowl¬ 
edge and general state of the art of milling; that is, there is a limit to 
the purification of middlings—a limit fixed by the present state of mill¬ 
ing knowledge. 

As milling is a general wheat-cleaning and reduction process, it must 
be clear that the distinction between wheat cleaning and middlings 
purification is merely a distinction for the sake of classification, and not 
one in fact, the general purpose being the same, whether the wheat be on 
the cleaning machine or on the purifier. The distinction by nomencla¬ 
ture can be no broader, founded on no other reason than the purpose 
of classification or convenient distinction. 

As has been said before, the cleaning of wheat or the cleaning of mid¬ 
dlings renders it in a measure possible to separate the impurities from 
the stock before its final reduction into flour and before the stock gets 





GRADUAL REDUCTION MILLING. 


I 9 7 


into the Hour reels. In this statement may be found a broad distinction 
between new and old process milling. According to the old process, 
after the wheat had passed through the primary cleaning machines, it 
was reduced suddenly and sent into the Hour reel in a mass—bran, Hour, 
middlings, impurities and all alike—and while in this condition certain 
stock was taken through Hour numbers of the cloth, for which rea¬ 
son it was barreled and sold as Hour, the material out of which to make 
bread. Any of the impurities which were kept out of the flour had to 
pass the whole length of the bolting apparatus to get out. The impu¬ 
rities, instead of being the first particles to be removed, were the last, 
and, as a necessity, certain portions of this material went in with the 
higher grade of Hour. A system of milling to which allusion has been be¬ 
fore made, which separated the impurities from the other stock after it 
had passed through with all the other good material, could hardly be 
one which would survive. It was supplanted by the later methods—the 
general purification system—which seeks to separate the impurities from 
the Hour while it is yet middlings. It would be entirely successful but 
for one fact. It is not entirely possible to reduce all of the wheat into 
middlings without incidentally making flour. 

If it were possible to make all middlings, it would be possible to take 
away a large proportion of the impurities of the wheat before any of 
the stock was reduced to Hour. It is the measure of the success of the 
operation of middlings making which fixes the measure of‘excellence of 
the later processes of milling above the older; it is because the wheat 
may be purified to a certain extent before the stock is sent into the reels 
for the purpose of making the Hour separations. It is common in some 
of the mills to begin taking Hour from stock which contains coarse mid¬ 
dlings; that is, stock which contains Hour and middlings—flour which 
has been made during the course of middlings reductions. 

As a means of carrying out the idea of the system of separations 
which has been brought about during the years of middlings milling, it 
would be well to apply, in so far as possible, the system of removing as 
large a proportion of the impurities as is possible from the Hour stock— 
stock which is too fine for partial purification by the oidinary methods, 
before sending it to the Hour numbers 01 befoie making lloui sepaia- 
tions. This process has been illustrated by remarks in regard to the 
reduction of the proportion of soft material dining the piocuss of mak¬ 
ing Hour separations. This is as far as the system can be canied out 


198 


GRADUAL REDUCTION MILLING. 

in the bolting of the finer grades of stock—stock too fine or too small 
as to the size of the granules to admit of its being handled by sieves 
and suction machines. The finest middlings which it is usual to handle 
by such machines is the grade which will tail over a No. 9 cloth. 

It is fair to say that with this grade, and grades as coarse as will pass 
through a No. 5 and 6 cloth, that purification is more largely owing 
to the sieve action of the purifiers than to the suction action, the dis¬ 
tinction between the specific gravity of the impurities of this lighter 
grade of middlings being so small that it is hardly possible to so nicely 
adjust the air currents as to make the separation on these grades of 
stock. However, the sieve action is such as to recognize the nicer and 
finer differences. The lighter particles of stock will be brought to the 
top by the vibratory motion, or the oscillatory motion of the sieve, and 
in this way, if the machine is properly cared for, the impurities will float 
toward or over the tail. With sieves that handle this grade of stock, it 
would be well that they do not have so severe and quick a motion. While 
it is highly important that the sieves of all the purifiers should be entirely 
and evenly covered from head to tail, or to that portion of the tail c'oth 
where it isTo longer desirable to take off clean middlings, it is positively 
fatal to the successful operation of the machine which handles the grade 
of middlings previously alluded to, not to have its sieve so covered. 
This grade of middlings receives less benefit from the action of the puri¬ 
fiers than does any other coarser grade. It is fair to say that the grade 
of middlings which will tail over a No. 4 cloth and pass through a No. 
2 makes the greatest showing of benefit from the action of the purifiers. 
The coarser middlings are as largely benefited, though they do not show 
it so plainly. The larger the middlings the more readily are they bene¬ 
fited by the action of the air currents. The larger the middlings the 
greater the difference between their specific gravity and that of 
the impurities; hence the ease of the separation by tlie air currents. 
There comes a point w r here the broken particles of wiieat are too large 
to be handled advantageously by the purifiers and other machinery in 
use in most mills. 

The sizing of middlings, which operation may be applied to middlings 
coarser than those which will pass through a No. 6 cloth, is the most 
successful method which maybe adopted for their purification, not only 
from the fact that it will release the attached impurities and flatten the 
germ, but because it will make other positive separations. 





GRADUAL REDUCTION MI LUNG. 


I 99 


In support of the idea that middlings which will pass through a No. 5 
or 6 cloth cannot be appreciably benefited by the suction action of the 
purifiers, it is called to mind that middlings of this grade are seldom or 
never purified when they are the product of sizing rolls or other mid¬ 
dlings reduction machinery. The most successful method of purifica¬ 
tion for this grade of stock is the smooth rolls and the accompanying 
reels. 


CHAPTER XXXIV. 


GENERALITIES IN REGARD TO THE MIDDLINGS IDEA-REMOVAL OF IMPURI¬ 
TIES-DIFFERENT KINDS OF IMPURITIES—MEANS ADOPTED FOR THE 

PURPOSE OF THE REMOVAL OF IMPURITIES—THE SIZE OF MIDDLINGS, OR 

PURIFICATION—DIFFERENT KINDS OF PURIFIERS-SMOOTH IRON ROLLS 

-A GRAVITY SEPARATOR. 

Having introduced this subject in the last chapter, by such general 
comment as die importance of the subject would suggest, the features 
which apply to the direct purification of middlings will now be taken up. 

There are certain parts of the wheat which are deleterious to its bread¬ 
making qualities when reduced to flour. The purification of middlings 
has in mind the removal of such portions. This is a broad statement 
of what is to be done in the purification of middlings. Such impurities 
cannot be removed without breaking the wheat up into small bits—that 
is, middlings—and then removing the impurities. Some of these impu¬ 
rities, and the most notable, are the vegetable hairs ; the germ, its coat¬ 
ings and surroundings; the bran, and the interior cellular coatings. This 
statement will convey as good an idea of the impurities and aid as much 
in the description of their removal, as if it gave the exact technical com¬ 
position. 

As the purification means the removal of these impurities, the basis 
of separations must be considered. There must be a difference some¬ 
where in order that there may be a separation. If it were possible for 
the impurities to be of approximately the same character as the desirable 
portion of the wheat, the purification could not be accomplished. But 
there is always a difference in the physical composition where there is a 
difference in the chemical or other qualities, and where the difference is 
sufficiently great the separation can be made by mechanical means. The 
purification of middlings has to be done on a commercial basis, and it 
will be so considered. 

According to present methods the basis of separations is size, specific 
gravity and general structure. For example, the impurities may be 
lighter than the middlings, as in the case of the woolly fibre, or they may 


GRADUAL REDUCTION MILLING. 


201 


be larger, as with bran, or the structure may be entirely different, which 
makes it so easy to separate the germ. The above illustration, being 
merely descriptive, does not pretend to enumerate the different impuri¬ 
ties coming under the distinctive qualities named. 

The differences of size, weight and structure are those which make 
the purification of middlings possible. They suggest the construction 
of all purifying devices. 

Knowing these qualities, we are now to consider the agencies of puri¬ 
fication ; that is, the machinery of purification. The separation as to 
size is accomplished by means of bolting cloth; as to specific gravity by 
air currents, which allow the heavier particles to pursue one course and 
compel the lighter to take another; as to the structure, by means of re¬ 
duction machinery, which reduces the middlings and allows the impuri¬ 
ties to remain intact. For example, as to the latter, the smooth rolls 
may be mentioned, which make a germ separation possible. These 
agencies being mechanical, there are differences which are not recog¬ 
nized by the various devices. There are impurities in the smaller por¬ 
tions of broken wheat which are of less specific gravity than the desir¬ 
able portion, and, because of the difference being so small, their purifi¬ 
cation is not possible on a commercial basis. This is what makes the 
purification of flour impossible, as it is also a good reason for the pro¬ 
duction of larger particles, i. e., middlings. In many of the best mills, 
only such middlings as will tail over a No. 8 or 9 cloth are treated on 
what are generally known as purifiers. This involves the dusting of the 
middlings—that is, taking out ail that portion which will go through a 
No. 8 or 9 cloth—and the scalper or dusting reel can be considered as 
an auxiliary purifying device when the term purification is applied only 
to middlings. 

It is not the writer’s purpose to go into a description of machines 
with which every one is familiar, but merely to record such ideas as he 
may have on the general principles of their operation. The separation 
as to size and specific gravity is ordinarily made, as every miller knows, 
on a vibrating sieve machine—with a current of air up through the sieve— 
the lighter impurities going in the direction of the air current and the larger 
impurities toward, or perhaps over, the tail of the sieve, while the pure 
middlings go through the cloth. This is the most common form of purifier. 
Another has the sieve to separate the larger impurities as before, while 
the middlings and a portion of the lighter impurities of corresponding 


202 


GRADUAL REDUCTION Mil.LING. 


size go through the cloth in size varying as do the meshes, and thence 
by gravity through an arrangement of slats or surfaces arranged to de¬ 
flect the middlings to various positions so as to be exposed to currents 
of air which allow the middlings to pursue their general downward course 
and draw the lighter impurities in the direction of the current; that is, 
horizontally for the most part, and at right angles to the course of the 
pure product. The Hagenmacher, the Worner, the Seek and Gray puri¬ 
fiers are notably samples of such machines. The centrifugal purifier has 
a revolving disc on which the middlings are fed and under which there 
is a current of air drawing inward. The centrifugal force of the revolv¬ 
ing disc throws the heavier particles to a greater distance than the smaller 
ones, and into receptacles prepared therefor. The lighter portion has a 
tendency to fall nearer the disc and the light impurities are drawn under 
and entirely away from the body of purified middlings. 

The above mentioned machines are what are ordinarily described as 
purifiers. In the category the writer wishes to include the smooth iron 
rolls, which aid in making a separation by reducing the clean stock and 
allowing the impurities to remain large or their original size, so that they 
will pass over the tail of a cloth, while the former passes through it. 
There is no way to separate the sizing rolls from the purification system, 
and the diagrams and descriptions which are to follow will include them 
in the exhibits made. As will be seen, the product of the middlings 
from the mill cannot be purified in any degree of completeness and 
economy without the use of the smooth iron rolls. There are certain, 
grades of large middlings which can only be purified up to a certain 
point considerably removed from the proper degree of purity without 
their use. They are not only for the purpose of changing the relative 
size of the clean stock and the portion to be removed, but also to change 
the relative specific gravity of the different parts, at the same time re¬ 
ducing the stock and liberating the impurities. Smooth iron rolls, in 
combination with separating devices, are as much entitled to the name 
of purifiers as sieve and suction machines. 

The cuts which are given do not pretend to represent the fullness of 
the ideas expressed, but are illustrative of the general principles of a 
system which will be shown more in detail another time. The mechan¬ 
ism of the ordinary sieve and purifier is well understood by all millers, 
therefore a description, gene al or otherwise, would be wasted. 

The cross section shows a gravity separator or aspirator, which may 






GRADUAL REDUCTION MILLING. 


203 


need a little explanation. It is a form of purifier which is largely used 
in Hungarian milling. Not this particular one, but of the kind and gen¬ 
eral principle which is described in this chapter. 

The purifier here illustrated is a suction machine. The direction of 
the suction is between the slats E and E, and toward the opening B , 
the size of which opening and the force of the suction are regulated by 
the valve E. The middlings pass between the slats E and F in a down¬ 
ward direction and are deflected from side to side, their progress being 
arrested by these. The suction draws the particles of less specific gravity 

than the good middlings through the 
openings y'and over the slat E into 
the chamber at the back thereof. 
The air, after it passes through the 
narrow openings, expands to a cer¬ 
tain extent and allows the larger 
portion of the impurities to settle 
and discharge through the opening 
G , which has a slat covering it in a 
manner similar to that of the dis¬ 
charge of a separator shoe. The 
pure middlings discharge through the 
opening H. For this kind of a purifier it is important that the mid¬ 
dlings passing down each kg or compartment should be of the same 
size; that is, they should be graded very close. There should not be a 
difference of more than one number from one compartment to the next, 
or from one size to the next. By this means the suction can be adjusted 
according to the specific gravity of the middlings, and thus make a 



nicer distinction between the specific gravity of the good middlings and 
the impurities. If the grading is done on grits gauze numbers, the siz¬ 
ing can be done much closer than by a bolting cloth, as the grading is 
much closer. There are several sizes of grits gauze numbers to one of 
bolting cloth. For example, No. o of bolting cloth is represented by 
No. 36 of grit gauze, and No. 00 by No. 28, between which there are 
the intermediate numbers 34, 32 and 30. When the numbers are finer 
than 000, there are no intermediate numbers. With such machines there 
is the grading sieve above, which in the cut is represented by A B , which 
is arranged to grade the middlings into the different sizes mentioned, the 
cloth being nearer the top, and the discharge openings as repiesented 



















204 


GRADUAL RKDUC'L'ION MILLING. 


by C, which allow the middlings to fall through to the slats, to be acted 
upon as described. The middlings which fall through the cloth in front 
of the opening C are conveyed to that opening on the flat bottomed 
piece B, by the sieve action. These purifiers are generally constructed 
with four legs to each machine, which requires that this sieve be arranged 
to grade into as many different sizes. 

The purifier just described is regarded by the writer as the best possible 
one for middlings which are coarse enough to tail over a No. 2 or 3 cloth. 
They are more effective as to their operation and make a cleaner, closer, 
more decided separation, with less waste and fewer operations than any 
other machine. They require less attention, and are therefore more 
economical as to operation. They are also cheaper as to first cost. 


CHAPTER XXXV. 


THE GRADING OF MIDDLINGS-A SIEVE GRADER DESCRIBED—AN ASPIRA¬ 

TOR UNDER THE GRADER THE NUMBER OF GRADES OF MIDDLINGS 

THE GRADER AS AFFECTING THE NUMBERS OF CLOTHS ON PURIFIERS. 

The grading of middlings, previous to purification, is worthy of seri¬ 
ous consideration. In past years this grading has, for the most part, 
been done on reels. On the system which will be here described, and 
the diagram given, the grading will be done on sieves or shakers. By 
this means the middlings are graded without making dust -- at least, there 
is less dust than by the other methods, and then there is the purifying 
effect of the sieve action. The value of this sieve action is largely un¬ 
derestimated. Its action is more potent than it is credited with being. 
It has more to do with the purification of middlings than do the cur¬ 
rents of air, as provided for on the ordinary form of purifiers independ¬ 
ent of such action. By the swinging hand-sieve motion, the impurities 
are left on the top, and the heavier middlings are next the cloth. This 
motion has the effect, in a modern degree, of constantly lifting and 
tossing the stock on the sieve. The middlings being heavier, they fall 
next to the cloth, while the light impurities are above, and thus are 
finally passed over the tail of the sieve. All this presents another good 
feature of sieve graders. 

The best grader known is one long sieve or more. It does not make 
as much flour as a reel grader, and at the same time it has a purifying 
action, because of the sieve motion. A sieve forty inches wide and 
twenty feet long will do all the work of grading for a 250-barrel mill. 
Such a grader is a very simple affair, and very easily made. It should 
have an inch throw on the eccentric, which should be speeded at about 
350 revolutions per minute. The frame of the sieve proper should be 
supported on hickory springs, which should be about three feet long. 

As to the grading of the middlings on this machine, assuming, ac¬ 
cording to the diagrams given, that they have been dusted over a No. 9 


206 


GRADUAL REDUCTION MILLING. 

cloth, and the whole body, coarse and fine, has been run to this ma¬ 
chine, the following clothing suggests itself: 

4 3 2 o oo 

This does not necessarily mean that there will be this number of grades 
of middlings to be purified, but they are divided in this way in order to 
derive the benefit from aspirators, (one of which is used for each grade,) 
which are set under these graders. One aspirator, or a single leg there¬ 
of, is used for each grade of middlings. A very good form thereof is here 

illustrated. It is somewhat differ¬ 
ent from those formerly given. The 
middlings drop from each section of 
the grader, and of a size as sug¬ 
gested by the numbers of the cloth, 
into the opening A, and through the 
slats, as shown, in a zigzag direction, 
and as controlled thereby. The 
middlings pass out through the open¬ 
ing B. The direction of the suc¬ 
tion is from C to D , the volume of 
which is controlled by the valve R. 
There will be drawn out a large 
amount of impurities, the heaviest 
of which will pass through the shoe 
valve F. This stock should be sent 
to the tailings. Above the aspira¬ 
tor, as indicated, is a part of the 
sieve. G is a rigid bottom made 
with a light board, and H is the 
grading cloth. After these mid¬ 
dlings have passed through the aspi¬ 
rators in the number of grades as indicated, they may be spouted to¬ 
gether into a smaller number of grades, and from thence to the purifiers. 
The 4 should form a grade by itself, the 3 and 2 another, and the o and 
coarser a third. The first two grades it would be well to purify on the 
ordinary sieve and suction machine, and the coarser middlings on an 
aspirating purifier, of the pattern similar to the Gray, Worner, or other 
machines of that class. This is the least number of grades which the 
writer would suggest for a mill which intends to compete with the ordi- 
































GRADUAL REDUCTION MILLING. 


207 


nary run of merchant mills. There will be still another grade of mid¬ 
dlings from the sizings. 

As to the number of purifiers required, two for each grade is the least 
number which may be be suggested for mills of the class named. 

The practice of putting many different sizes of middlings on such a 
machine is fatal to its successful operation. There are more machines 
running which are clothed with No. 9 or other fine numbers at the head, 
and No. 2, r or o at the tail, with intermediate numbers between, than 
there are with better clothing. As the separation as to specific gravity 
is dependent upon the difference between the specific gravity of the 
middlings and the impurities, and as each size of middlings has an ac¬ 
companying quantity of impurities of the same size, there will be as 
many grades of impurities, and as widely varying in specific gravity, as 
there are different sizes of middlings on the sieve. Therefore, where 
the range is as wide as mentioned, the currents of air cannot be adjusted 
to meet the specific gravity of the various impurities and at the same 
time allow the middlings to take their desired course. For example, the 
specific gravity of the impurities of the coarser middlings may be as great 
as that of the finer middlings regardless of the impurities. Thus, a cur¬ 
rent of air which was adjusted to take out the lighter impurities from 
the coarser middlings, would take with it the fine middlings themselves, 
thus resulting in waste. It will be seen that it is important that only 
middlings of approximately the same specific gravity should go to a ma¬ 
chine. There should be different machines for the different grades. 
This will suggest that the machines should be small and numerous. 
With the gravity separator, where the middlings are not subjected to the 
action of the air until they have passed through the sieve, the number 
of different sizes is not so important with reference to the sieve, but very 
important as to the uniformity of size of the particles fed into each leg. 
It is one decided advantage for this form of purifier that it grades the 
middlings with exactness before they are submitted to the action of the 
air, and as the difference in specific gravity is greater between middlings 
and impurities of the same size than it is with the varying grades of mid¬ 
dlings and impurities before mentioned, the separation is sure to be more 
exact than it is possible to have it by other means. 


CHAPTER XXXVI. 


HUNGARIAN METHODS OF PURIFICATION-THE METHODS IN A HUNGARIAN 

MILL—HUNGARIAN METHODS NOT APPLICABLE TO AN AUTOMATIC 

SYSTEM. 

This chapter on purification is an interruption in the scheme originally 
laid out. In our present milling methods we have respect for and de¬ 
sire knowledge in regard to Hungarian milling, and whenever we meet 
any one who knows anything about such milling we are anxious to talk 
to him and find out what we can with reference to their methods; but it 
is not common to meet with such persons, and especially with those who 
have anything more than a hearsay knowledge in that direction. Hun¬ 
garian milling can no more be learned by walking through Hungarian 
mills and talking with Hungarian millers and engineers, than can Amer¬ 
ican milling by those outside by the same means. Bringing home a valise 
full of samples and a memorandum book full of isolated facts and figures 
does not represent the fullness of Hungarian milling. If one were to 
describe a Hungarian mill, he might describe something different from 
what some of the readers may have seen or experienced in that way, 
and it might be they would say his description was not accurate. On 
the same principle, three American gentlemen might meet on the Sand¬ 
wich Islands, or at home, for that matter, and discuss American methods, 
and no two of them would be able to agree exactly as to details; but 
this condition of things would not disturb the fact of their intimate 
knowledge of the subject under discussion. The details of W. C. & 
Co.’s mill may be different from that of P. & Co.’s, yet both may be do¬ 
ing good work. 

The writer’s knowledge of Hungarian milling is limited, but having 
taken notes of conversations with gentlemen who are abundantly sup¬ 
plied with such knowledge, which has been gained in the active discharge 
of their duties in operating Hungarian mills, if he should make such 
mistakes in what he may have to say on the subject of purification as 
to bring out criticism and comment from those better informed, he would 
regard the result as beneficial to the milling fraternity as well as himself. 







209 


GRADUAL REDUCTION MILLING. 

In one of the mills in question there were six reductions of the wheat 
on rolls, and two or three reductions of the bran on millstones. The 
reductions on the rolls were much more gradual in this instance than in 
American mills. Thus the product of the various reductions cannot be 
spoken of as compared with those of the same reductions with us. 
In this mill the middlings from the second and third reductions were 
purified together and the fourth and fifth by themselves. The wheat or 
stock having passed through the rolls and thence through a scalper, the 
tail goes to the next reduction, and the product of that reel into the 
Hour reel clothed with Nos. 13, 14, 15 and 16 cloth, the tail of which 
reel is the dusted middlings, which middlings pass into a reel clothed for 
grading them. The clothing of this reel is represented by the figures 
below: 

68 60 56 52 46 40 36 30 24 22 

The product of each division of this reel—each division being by a 
number—composes a separate grade of middlings. Thus it will be seen 
that from grade to grade very few numbers are skipped, and the relative 
difference from one size of middlings to the next is very slight, which, as 
before described, renders it possible to purify the middlings economically 
—that is, with small loss—making the separations with reference to the 
specific gravity of the middlings and impurities. Each grade of mid¬ 
dlings passing through the numbers mentioned is treated on purifiers 
especially clothed and regulated as to the volume of air for the class of 
middlings to be handled. The first two grades, those which pass through 
Nos. 68 and 60, pass to a grading sieve where they are graded into in¬ 
termediate numbers, from 70 to 56 inclusive, and each number or size rep¬ 
resented thereby to a centrifugal purifier, and from thence as purified 
middlings. These middlings make Nos. 1 and 2 flour (Hungarian grades) 
when reduced, the best flour being represented by o. The remaining 
coarser grades of middlings, commencing with No. 56 and ending with 
No. 26, are purified each on independent machines, with the grading 
number, and intermediate numbers of cloth. These machines are of 
the aspirator pattern, and in the mill which the gentleman had in mind 
when talking to the writer, they used the Worner machine, a number of 
which are in use in this country. The middlings which would pass 
through a No. 56 cloth would go to a machine clothed with Nos. 60, 58 
and 56 cloth, and those through No. 52 to a machine clothed with Nos. 
56, 54, 52 and so on for each grade clothing in the same way. Each 

(* 4 ) 


2 10 


GRADUAL REDUCTION MILLING. 


leg of each machine makes another division of stock of two additional 
grades—that is, the purified middlings and another grade partially puri¬ 
fied, which are drawn over in the manner described in Chapter XXXV., 
excepting that the suction was much stronger than was contemplated 
with the machine therein described. By a single operation on this ma¬ 
chine, with strong suction, there is obtained one grade of purified mid¬ 
dlings for each leg, and one partially purified. The purified middlings, 
beginning with the coarsest, are sized down one grade at a time; after 
each sizing the flour being taken out, and the middlings passed through 
a reel clothed Nos. 8, 7 and 6 cloth, the tail of that reel passing to the 
next reduction. The product of the Nos. 8, 7 and 6 cloth is purified 
middlings which reduce to o, or the best flour, excepting perhaps in the 
case of the grade represented by the No. 6 cloth. The sizing of these 
middlings, as said before, is from one coarser grade to the next finer, 
and so on. By each grade is meant the grades as represented by the 
clothing of the purifiers and not by the grading reel, as previously men¬ 
tioned. As they size the lower number it goes to the next higher num¬ 
ber, or that which produces the next grade finer middlings. Thus all 
the middlings are reduced to such an extent that they will pass through 
a No. 8, 7 or 6 cloth, the operation of dusting the flour out of the mid¬ 
dlings, and passing them over a reel so clothed being repeated for each 
sizing. The flour from the reel which dusts these sizings is No. 1 or o; 
that is, the best. 

The unpurified or second grade of middlings which are drawn over 
the leg of each aspirator are passed through rolls and touched lightly, 
each grade by itself, and run into a reel to take flour out, from which 
they tail over to a grading reel, which is clothed the same as the one 
described. This sizing is done merely to change the gravity of the mid¬ 
dlings previous to the next purification. Having been graded as de¬ 
scribed they pass for purification to machines of the same kind, and 
clothed and operated in the same way, as those for the first purification. 
The purified product from the purification is treated the same as the 
middlings from the first purification; that is, it is gradually sized, dusted 
and graded, until it will pass through a No. 8, 7 or 6 cloth. The unpu¬ 
rified product—the part drawn over in the purification of the other grades 
—is again subjected to the treatment just described, until the remaining 
stock is not worthy of purification, after which it is worked down on 
smooth rolls. It should be remembered that in Hungarian milling the 



GRADUAL REDUCTION MILLING. 


2 I r 


stock suggests the method of manipulation by means of the various; 
milling machines. The stock being handled by hand for the most part, 
this course is rendered possible and convenient. In an American, or 
automatic mill, the course of the stock is arbitrarily fixed by the con¬ 
veyors, elevators and spouts. In a Hungarian mill, where the stock is 
run into sacks or buckets, its inspection is convenient and the method of 
treatment is suggested thereby. 

The above is the outline method of purification in at least one Hun¬ 
garian mill which did good work, and it probably resembles many others. 

The facilities for inspecting the middlings render it convenient to grade 
the purified product with reference to quality, which quality, other things 
being equal, will determine the grade of the Hour. 

The best grades of purified middlings are reduced on millstones, and 
very gradually at that. From*the first three reductions of the best mid¬ 
dlings, the largest proportion of Hour taken out is No. o, or the highest 
grade. By the various subsequent reductions of this and other grades 
of middlings, successively lower grades of middlings and Hour are made. 

The methods described will show that a very large number of opera¬ 
tions are necessary in carrying out the scheme of Hungarian milling. It 
can also be seen that an absurdly large plant would be required to carry 
out this scheme in an automatic mill. This difficulty is obviated in their 
milling by the methods of handling the stock by hand, which render it 
possible to use one machine for various kinds of stock. One purifier 
may be used to purify any number of grades of middlings, by merely 
changing the sieve cloths, which are made interchangeable for that pur¬ 
pose. A single pair of rolls may be used for sizing or reducing various 
kinds of stock, or a pair of buhrs may be used as widely. And as to 
the reels, it is a simple question of adaptability in clothing, as to for 
what purpose they may be used widely. 


CHAPTER XXXVII. 


THE OPERATION OF PURIFIERS-PROPER COVERING OF THE SIEVE-EXACT 

WORKING CAPACITY OF PURIFIERS-PRINCIPLES WHICH REGULATE THE 

CLOTHING OF PURIFERS-EFFECT OF AN OVERSUPPLY OF STOCK ON THE 

SIEVE-EFFECT OF A FEED WHICH IS TOO LIGHT-MEANS OF REGULAT¬ 
ING THE CAPACITY OF PURIFIERS-CAUSES WHICH MAY LEAD TO A 

VARIATION OF THE PROPORTION OF MIDDLINGS MADE—FORM OF MID¬ 
DLINGS-MIDDLINGS MADE BY OVERGRINDING-FIFTH REDUCTION MID¬ 

DLINGS—METHOD OF PURIFYING FIFTH REDUCTION MIDDLINGS BY THEM¬ 
SELVES—DISPOSITION OF MIDDLINGS FROM THE VARIOUS BREAKS- 

CLASSIFICATION OF STOCK—THE RETURNING OF MIDDLINGS. 

In its operation, the common form of purifier requires that the mid¬ 
dlings should entirely cover the sieve, in a thin, uniform sheet, so that 
air in passing through can take with it the lighter particles—the impuri¬ 
ties. If the sieve is not covered at any one or more places, the air 
will come through such uncovered places, to the exclusion of others, as 
the air will come from the direction where the least resistance is offered. 
This covering of the sieve is important in any case, but more so where 
the action of the purifier is dependent upon the uniform passage of air 
through the sieve. 

If the sieve becomes bare, the action of the air currents, as far as any 
benefit to the middlings is concerned, is greatly disturbed, and at the 
same time the value of the sieve action—which is not to be overesti¬ 
mated—is almost entirely lost. The light impurities which would other¬ 
wise pass over the sieve by floating along on top of the middlings, are al¬ 
lowed to pass through the cloth and go to the next machine as a cut-off, 
rather than over the tail as tailing'. While the cut-off is of a lower 
grade than it should be, the quality of the stock at the head of the ma¬ 
chine is correspondingly reduced. 

It is well understood that a purifier should have enough to do, and 
yet not too much. It is vitally necessary that the sieve should be cov¬ 
ered. On the other hand, if the machines should have too much to do, 
the middlings would not be clean, and there would be waste at the tail. 
This thing can be partially regulated by the proportion of coarse and 




GRADUAL REDUCTION MILLING. 


213 


fine cloth. r l he head and tail numbers are easy enough to determine, 
and the intermediate numbers may be readily supplied. The quantity 
of each requires judgment and experience and a knowledge of individ¬ 
ual cases. Say we want to determine the head and tail numbers for the 
middlings which come through the Nos. 3 and 2 cloth. In the present 
instance it would be well to use the numbers at either extreme of those 
mentioned. Tnis would mean 4 for the head number and o for the tail 
number. The amount of 4 to be used would depend largely upon the 
amount of middlings to be handled, and of the o only a very small por¬ 
tion in any case, because it is only put there to cover the contingency 
of the machine tailing over, when it has more than an ordinary amount 
of work to do. Perhaps No 1 cloth would be better in many instances. 
The fact of the tail of the grader being clothed with 00 may look like a 
mistake, considering the fact that the coarsest middlings pass through a 
000. This may be explained by saying that an aspirator with a heavy 
suction should be placed so as to take all stock going over the tail of 
the grader. From here it would go on to the coarse middlings purifiers. 

An oversupply of stock in the sieve impedes the action of the 
suction, in that the air cannot pass through the volume of stock in a 
way to separate the impurities. At the same time there is stock going 
over the tail which does not belong there. The extreme of light and 
heavy feeds may be practically illustrated in a mill more than once in a 
day. It might be said that in “case of a light feed, raise the feed gates,” 
but if there were no more midd.ings in the mill, this would do no good. 
In case of heavy feed, it will not do to lower the feed gate, as this is 
not getting rid of the accumulation. 

In the foregoing, the clothing of a machine was mentioned as one 
consideration which would affect its capacity, and it was stated that the 
proportion of coarse or fine cloth could be increased or decreased ac¬ 
cording as it was intended to increase or decrease the capacity of the 
machine. Another way of effecting this same result, mention of which 
was omitted in its proper connection, is by changing the speed and 
throwing off the sieve. We will say that the machine has too much to 
do, that the middlings lay thick and heavy on the cloth, and for that rea¬ 
son tail over heavy and rich, and, as a consequence of the sieve being 
heavily loaded, the suction cannot do its work properly. A 1 this can 
be changed by increasing the number of vibrations of the sieve. Making 
it move faster would take a large body of middlings over the sieve 


214 


GRADUAL REDUCTION MILLING. 


in a thin sheet. If the feed were too light, a change in the motion of 
the sieve to make it run slower would cover the cloth; but this remedy 
is not practicable for ready adjustment, as few machines are so arranged 
that the speed of the sieve may be reduced without correspondingly di¬ 
minishing the force of the air currents, which is not desirable. 

Another, and by far the best way of regulating the capacity of a ma¬ 
chine, is by having an eccentric with a double sleeve, so that the throw 
can be changed at will. This is sometimes called a double eccentric. 
It does not mean two eccentrics, but rather one eccentric with a double 
sleeve. If the stock lies too thick on the sieve and the machine appears 
to have too much to do, the desired change can be made by increasing 
the throw of the eccentric. This is done by moving the inner sleeve in 
.such a way as to increase the throw as stated. This makes the stock 
travel faster on the sieve, and consequently in a thinner sheet. Where 
the machine has not enough to do—where the sieve is not covered 
—making the throw less will bring about the desired end. A change in 
the inclination of the hangers changes the speed of the stock on the 
sieve, but even on machines where this is a mechanical possibility, millers 
or purifier men are not inclined to do a thing which is so liable to en¬ 
tirely interrupt the regular movement of the stock, and any changes of 
the hangers are calculated to do this. The principle of their adjust¬ 
ment is that, where the resistance is greatest next the eccentric, the How 
of stock will be more rapid, and vice versa. 

As far as known, there is only one machine made with this double 
eccentric, and the millers who have used it have gained very little benefit 
from its being on the machine, as very little attention was paid to this 
matter of throw. In making some inquiries, the writer was led to be¬ 
lieve that this form of eccentric was first used in milling operations on 
.an oat separator. It maybe noticed that with one of these machines 
the matter of throw or speed makes a great difference in its operation. 
A little change one way or the other makes a marked difference in the 
result. The matter of a machine having just enough to do, neither too 
much nor too little, is of the greatest importance. No system of puri¬ 
fication can be so perfect in arrangement but that its work can be made 
inferior by a disregard of this matter. It is difficult to emphasize the im¬ 
portance of this detail sufficiently. This may be said, that no purifier 
can be under the control of the miller, nor can be made to work up to 
its possibilities at all times, without means of adjusting the speed or 





GRADUAL REDUCTION MILLING. 


21 5 


throw of the shaker, or some other means of adjusting its capacity. 
There are many causes which may lead to a variation in the propor¬ 
tion of middlings made in milling. This difference may be caused by 
changes in the feed on the mill, by the variable quality of the wheat, or 
by the variable qualities of those who run the mill. As the character 
of the wheat changes and hence the proportion of middlings, the qual¬ 
ity and general form thereof also changes. This same result may be 
brought about through the changes in the running of the mill when the 
wheat is uniform. The quality of the middlings is estimated, from a 
milling or mechanical standpoint, by the facility with which they may 
be purified. The middlings which are most readily purified are those 
which are free from flour; those which are made from breaking, not mash¬ 
ing the wheat, they being sharp and angular in form rather than flat and 
compressed. It is desirable that a granule of middlings should not have 
an excess of length in proportion to its thickness. The nearer the form 
approximates that of a cube the better, though it would be absurd to 
expect exactness in this respect. On the other hand, it is absurd to 
make long, stringy, or thin, fiat middlings. Good middlings are made 
by breaking the wheat, but not by rasping and mashing. Millstone mid¬ 
dlings from slow, high grinding are more readily purified than roller 
middlings. The reason for this is to be accounted for by the question 
of form. Stone middlings are more nearly square, or rather their dimen¬ 
sions are approximately the same in all directions. They are spoken of 
by millers as being “nice and round. ” The tendency of roller middlings 
is just the other way; that is, to being oblong or long, rather than round, 
this form being suggested by the direction of the corrugations, which is 
lengthwise of the roll. In the millstone middlings there is a smaller 
proportion which has particles of bran adhering to them. A handful of 
such middlings, as they come from the dusting reel, would look browner 
and more specky than the same middlings of the roller mill. In the 
case of the former the particles of bran would almost entirely disappear 
after being treated by the purifiers. With the roller middlings this is 
not the case. While they are much brighter in color before going to the 
purifiers, there is a larger proportion of granules which have adhering 
particles of bran. There are two reasons for this. One is in the nature 
of the reduction, and the other in the difference in size and proportion 
of large middlings. As to the nature of the reduction making the dif¬ 
ference, it is apparent that the rolls break a great deal of the wheat in a 


GRADUAL REDUCTION MILLING. 


2l6 

way to make the bran adhering middlings mentioned. Again, pieces of 
the outside of the wheat are often chipped out by the corrugations. As 
to the size and proportion of large middlings, which are the class that 
have the bran adhering to them, it is apparent that such proportion is 
much larger in roller mills than in the old millstone mills; that is, by 
the former method, there is a much smaller proportion of fine middlings 
than by the latter, and, at the same time, there are larger middlings made 
by the former method than by the latter. The presence of these large 
and branny middlings makes the process of purification a more elabo¬ 
rate and extensive one than formerly. It invites a larger number of 
operations and demands the elaborate system of sizings and repurifica¬ 
tions which is necessary to bring about the proper results. In this way 
the introduction of the corrugated rolls created a demand for a larger 
number of smooth rolls. It is by the latter that the middlings of the 
class referred to may be purified. Ky a system of gradual reduction the 
smooth rolls break the middlings from the bran in a way to render the 
latter separable from the good material. The bran remains approxi¬ 
mately intact—that is, without being broken—while the middlings are 
detached and broken therefrom. 

To return again to the question of form. The objectionable qualities 
are brought about, more often than otherwise, by overgrinding, either 
by grinding with too heavy a feed or by grinding too close. If there is 
any difference, the former is the worst. Under such conditions, the 
middlings are sure to be soft and clammy. Overgrinding at any one re¬ 
duction carries its bad effect through the mill. For instance, if the 
grinding capacity on the second break is cramped, the capacity to make 
good middlings on the third, fourth and fifth breaks, no matter how ample 
their grinding capacity may be, will be cramped. The same principle 
applies to smooth roll reductions. A bad second reduction affects every 
subsequent reduction. 

Fifth reduction middlings were mentioned before, but it is pertinent 
to mention them again in this connection. The idea which was in mind 
at that time, was that the reduction in bulk of purified middlings con¬ 
sequent upon their being left out or purified by a separate system, would 
not be so large as might be at first supposed. The fact of their being 
run in with the unpurified middlings would imply that they would be 
more difficult to clean, and, consequently, there would be a large bulk 
of rejected stock which could not be cleaned, and a large amount o 



GRADUAL REDUCTION MILLING. 


2 17 

material going into the tailings. Thus the result in purified middlings 
would not be proportionally as large, when compared with the original 
bulk of unpurified stock with the fifth reduction middlings in it, as it 
would be il this latter material were left out. In the latter event—where 
these middlings are purified by themselves—the middlings from the other 
breaks would be much cleaner before going to the other machines, and, 
for this reason, there would be less offal and waste in purifying them, 
and consequently not so large a difference in bulk between the purified 
and unpurified stock. The same idea will apply to the Hour. The mid¬ 
dlings could not be purified so well with the fifth break stock in them, 
and when it came to reducing the middlings after they had left the ma¬ 
chines and separating the stock on the bolts, a much larger amount of 
material would have to be rejected, than if the middlings were cleaner. 
Consequently the difference in the amount of Hour made will not be 
greatly changed by running out the stock in question. 

In speaking of the purification of middlings, nothing has been said of 
the special disposition of the middlings from the different breaks. The 
inference might fairly be drawn that all were thrown together, and, in so 
far as it would not influence the matter of purification, such a course is 
desirable on account of the expense and lack of complication. In a 
mill of ordinary size, or even quite large—say a thousand barrels—divis¬ 
ions according to the various characteristics make the devices of purifi¬ 
cation so numerous and varied, leave so little work for each division to 
do, that there is as much danger of poor work from this source as there 
is by running stocks of approximately uniform character together. As 
a matter of theory, the amount of stock which a system of purification 
has to handle does not influence one way or another the number of pu¬ 
rifiers in a system required to do the work. For example, there should 
be the same number of classifications of stock in a small mill that there 
are in a large one, and as the different kinds of middlings would require 
distinct handlings—require separate systems of machines—this would 
complicate matters to such an extent that the system of purification 
would be by far the largest and most expensive part of the mill, both as 
to the first cost and the expense of manipulation. Furthermore, such a 
large number of divisions would run the stock so thin and in such small 
streams that it would be hardly possible to do good work with machines 
of even the smallest size. 

In speaking of the different qualities of middlings as above, there was 


2 I 8 


GRADUAL REDUCTION MILLING. 


in mind those made by the various breaks. There have been mills 
built where there was a separate system of purification for each break, 
but there are very few millers who can think of using such a system; 
and, for many reasons, of which a few have been mentioned, this will 
never be a popular method. The middlings which tail over a No. 9 
cloth from the first break on winter wheat are bright and in good shape 
for purification, excepting that they are a little long rather than round 
or square. Those from the second break are in better condition in this 
respect, and are easily purified, but the third and fourth breaks, as every 
one knows, are the best in the mill. The fifth break middlings should 
not be handled with the middlings from the other breaks. They are small, 
and should have a system of machines of their own, though it need 
not be elaborate or complicated, and from this system there cannot be 
a large proportion of middlings taken which are good enough for patent 
Hour of the best quality. 

The system of returning from one reel or purifier back to a reel or 
purifier from which stock originally came, is one which does not meet 
with favor in modern milling. It is against the best ideas of separation, 
but is tolerated in some good mills in connection with the purifiers, and 
its effect is not regarded as the same as it would be in the case of the 
softer products of the reels. It is done for the purpose of stocking the 
machines; that is, giving them enough material to cover the sieve. In 
the system described this is not necessary, except, perhaps, in the case 
of the first machine separation. The machines which follow can be 
stocked by throwing a portion of the cut-off from the second machine 
of each series to the next series of machines. To accomplish this re¬ 
sult with the air purifiers or aspirators, elevators are sometimes used to 
throw from one series of machines to another, thus taking required por¬ 
tions of clean stock and throwing it to the next machine for the purpose 
of giving it a sufficient volume of stock to cover the sieve. This may 
be accomplished in a less satisfactory way by clothing the tail of the 
second machine of each series finer than the middlings that are intended 
to pass through it, and elevating them to the first machine of the next 
series. It is of the utmost importance that the sieves of purifiers, of 
whatever kind, should always be covered. As said before, the sieve 
action of the purifier is one of the most important elements of its effi¬ 
ciency, and one which is largely underestimated. The value of the sieve 
action will never be realized unless the sieve is covered. 




CHAPTER XXXVIII. 


A METHOD OF ARRANGING PURIFIERS WITH REFERENCE ONE TO ANOTHER 

-MIDDLINGS FROM DIFFERENT KINDS OF WHEAT—UNIFORM TRAVEL OF 

STOCK-SIZE OF MACHINES. 

Iii the last chapter something was said with reference to the varying 
quantity of middlings made in the mill, and that the volume of stock 
varied from time to time, and to such an extent that the purifiers could 
not always handle the middlings with equal facility, either on account of 
the large or small amount of such stock—in one case the feed being too 
heavy, and in the other too light. It is apparent that there are no ready 
means of changing the machines to meet these varying conditions, and 
at the same time it may be recognized as a mechanical possibility to de¬ 
vise means for so doing. The various principles upon which such me¬ 



chanical methods might be based were outlined in the last chapter. 
There are milling methods in the processes of handling stock which par¬ 
tially accomplish the desired result in the way of a uniform feed. They 
cannot, however, fully meet the demands of extreme variations in the 
volume of stock. Such a method is illustrated by the accompanying 
sketch. 

It will be noticed that no finished middlings are taken from the upper 
machines. This, however, may be optional with the miller, yet the best 
practice would suggest that it be arranged as here shown. Finished 
middlings are taken from the second machine, the upper conveyor being 
used for that purpose. The tail goes to the tailings rolls and the cut-off 
























220 


GRADUAL REDUCTION MILLING. 

to the next series of machines, which handle coarser middlings. In 
event of the volume of stock on grade No. i being too light to do good 
work, in that it does not cover the sieve, the cut-off may be increased 
to any extent, and thus the desired portion of imperfect stock is sent 
to the machine which handles middlings of grade No. 2, which is a grade 
coarser than No. 1. In the same way and for the same reason grade 
No. 2 may be cut off and sent to grade No. 3, but there are objections 
in carrying this thing too far, which objections are to be found in the 
fact that the value of the proper grading of the middlings is lost by send¬ 
ing middlings of a finer grade with those of a coarser grade to be puri¬ 
fied. For instance, those of grade No. 1 are finer than those of grade 
No. 2, and, while this objection may not be serious when only coarser 
middlings of No. 1 are sent to No. 2, still it is plainly to be seen that 
this thing may be carried too far. 

As to the quantity of middlings: There is another condition which 
might have been considered, and that is the varying qualities of the 
various grades. For instance, in grinding soft wheat, the proportion of 
large middlings is excessive, and of fine middlings the proportion is 
small. This is often noticed in grinding soft Fultz wheat in the winter 
wheat region. Hard Mediterranean wheat yields generally a larger pro¬ 
portion of middlings and of more uniform size than any other. In the 
case of the former—the Fultz wheat—over half the middlings in the 
mill will tail over a No. o cloth, but with the hard wheat this proportion 
is considerably reduced. There is a smaller proportion of middlings 
with adhering portions of bran. The proportion of long middlings is 
also much smaller; the broken hard wheat more nearly approaches pris¬ 
matic forms and is more easily purified. Middlings can be broken down 
much faster on hard wheat than on soft; that is, they can be reduced 
more at a single reduction, and without flattening or showing flaky. If 
the rolls were set as closely in sizing soft wheat middlings as those of 
hard, the reduced stock would be flattened to such an extent as to ren¬ 
der its proper purification out of the question. 

To return to the question of the variation of the proportion of mid¬ 
dlings of the various grades, it is clear that the proportion of the ma¬ 
chines and their clothing may be such that one set of machines may 
have at certain times all the middlings which it ought to handle, while an¬ 
other may not have enough. For this reason it is apparent that the de¬ 
mand for the means of regulating the capacity of machines as they are 



GRADUAL REDUCTION MILLING. 


22 I 


running in the mill, without reference to other machines, will in time 
make it an object for some of our millfurnishers to so construct and 
arrange the purifiers that this may be done. This might readily be 
accomplished by having a driving shaft on the purifier which is inde¬ 
pendent of the eccentric shaft, both of which shafts—driving and eccen¬ 
tric—could have cone pulleys, so that the speed of the eccentric shaft, 
and consequently the movement of the sieve, could be controlled at 
will and in a manner independent of the speed of the fan—the latter 
being driven from the driving shaft of the machine—the motion of which 
would not be changed. The writer remembers to have seen purifiers 
which had cone pulleys on the fan and eccentric shafts, the purpose of 
which was to vary the motion of the former. It is difficult to conceive 
of conditions which would make such an arrangement imperative, but 
the benefits would be derived from arrangements which would vary 
the movement of the sieve in a way to always keep an even and 
regular body of middlings passing over the sieve at all times. It should 
run faster when the volume is greater and slower when it is less, and in 
this way compensate for the difference. 

In many mills, the millers do not take occasion to see that there is a 
uniform travel of stock over the sieve, one reason for which is that it is 
not always convenient to look inside, because of the way in which the 
doors and rick-sash are arranged. There are very few mills where there 
is enough help to keep the glass clean. Because of the liability of glass 
to get broken, and in this way to do much damage to the cloth on the 
purifiers and elsewhere, it might be a very good thing to fill these sash 
with light wood or tin panels, and then provide peep-holes with covers. 
This would make the matter of the inspection of the travel of the stock 
very simple and easy. It is clear that a miller cannot know that the 
sieve is covered unless he can see it, and it is equally apparent that he 
cannot see it unless there are proper and convenient means of inspec¬ 
tion. Furthermore, he cannot purify his middlings unless the sieve is 
properly covered with a uniform and thin sheet .of stock. 

The writer has been in a large number of mills where the stock was 
all coming down in one corner of the hopper and moving along on one 
side of the sieve, with at least two-thirds of the cloth bare. This is 
barbarous work. In many mills, relics of the early times of purifiers, 
in the shape of 14 and 16-foot machines, are to be seen. These same 
machines are run, working alongside of and handling the same volume 


222 


GRADUAL REDUCTION MILLING. 


of stock as an 8 or io-foot machine. One of these machines has en¬ 
tirely too much to do or the other not enough, it being probably the 
large machine which has not enough to do. Eight and io-foot machines 
are the best. Aside from the fact of being easier to get the proper air 
currents through the sieve, it is easier to get a uniform disposition thereof, 
independent of the condition of the travel of material. 





CHAPTER XXXIX. 


DUST COLLECTORS-THE ORIGINAL DUST COLLECTOR IDEA—THE OLD DUST 

ROOM-DUST COLLECTORS AS NOW MADE-CLASSIFICATION OF STOCK 

FROM DUST COLLECTORS. 

It will be well to consider another product of the purifiers, one which 
does not usually come up for consideration in the treatment of milling 
questions in a practical way, and that is the material from the dust col¬ 
lectors. Dust and Hour mills have been regarded as inseparable. The 
minds of millers have been changed considerably in this respect during 
the last few years. Dust collectors and general good construction have 
done a desirable service in making it possible to keep the mills free from 
the annoying clouds of dust. It is remembered when the Washburn 
dust collector was first talked of, and the speculation in regard to it. 

Before that time it was a common thing to say that the man who would 

% 

invent a dust collector for a purifier had a fortune. But this was one of 
the machines which a number of people seemed to work out about the 
same time, and the general principles were approximately the same in all, 
while each had certain good points in detail. The dust from the mill, 
the spouts, the bins, the rolls and all should be forced into such collect¬ 
ors, and every precaution taken to make the mill a cleaner, brighter 
place than tradition and history have decreed that it should be. The 
manufactory of so prominent a food product, and one which strives for 
such purity, certainly calls for cleaner and purer surroundings than are 
usually allotted to it. 

The dust problem and the collection of dust from the purifiers was 
one of the most perplexing questions with which ail had to deal during 
the process of working out the middlings idea. Among the many 
methods undertaken was that of constructing dust rooms where the cur¬ 
rent of air was merely intercepted by shelves and partitions, where it h id 
to go by circuitous routes in order to reach the outside air. This was a 
troublesome arrangement, requiring frequent cleanings of stock that 
lodged in and about the partitions and shelves, and really saved but a 
small proportion of the material which went into it. It was a common 


224 


GRADUAL REDUCTION MILLING. 

thing in those days to see the outside of the mill, the roof, and frequently 
the surrounding neighborhood, covered with Hour and middlings dust. 
Next came the balloon frames, covered with muslin, which promised very 
well, and then the muslin dust rooms, with their zigzag exteriors. But 
the meshes of the cloth were soon filled up, and there was trouble with 
back pressure on the machines. 

It appears now that the dust collector problem is pretty well settled, 
and for two reasons. In the first place, there is less dust than there 
was in past years—less dusty middlings to be handled—and, second, the 
mechanical devices and principles involved are different from those of 
the earlier times. In the dust collectors of the present time that are 
successful, the use of flannel, with blast or suction, or a combination of 
the two, through this flannel, and the arrangements for cleaning it, is ac¬ 
cepted as the proper thing. Several years ago, when middlings were 
dusted over a No. 12 and No. 14 cloth, when the mills were full of re¬ 
turns, and when so many millers tried to purify flour, it is questionable 
if the dust collectors of the present time could have been successful. 
The dust collector is the most successful, and does the best work, where 

the other milling operations are carried on most skillfully and intelli- 

« 

gently. Most of the trouble with dust collectors has been where the 
millers have attempted to separate the flour from the air. 

The dust collectors, as they are now made and put on the market, 
have passed the experimental stage. They are successful machines. If 
we were not well acquainted with the practical performances of these 
collectors, we could be certain of the statement—would feel justified in 
making it—for other reasons than those of personal observation. We 
have seen and know of business men who have made investments in 
machinery for manufacturing these collectors. They have put large 
sums of money in the business, have been engaged in it for several years, 
and are apparently prosperous. No firm can manufacture and sell at 
a profit and continue to manufacture, as have those engaged in this busi¬ 
ness, while making a machine that is not a practical success, and which 
will not do what it is intended to do. When we hear millers and others 
condemning a machine which has been successfully manufactured and 
sold for several years, and of the successful operation of which in many 
other mills, or in other instances we are assured, we cannot but believe 
that they are expressing their own incompetency at the same time they 
are condemning the machine. A machine which is successful in a hun- 


GRADUAL REDUCTION MILLING. 


225 


dred instances, cannot be said to be an experiment in other cases where 
the circumstances are similar. No business man is going to continue to 
manufacture and sell an inferior machine for any great length of time. 

Of the various methods for arranging collectors and att .ching them 
to machines, that of having one for each purifier is preferable to all 
others. Or if, for economic reasons, this plan be not adopted, it should 
be borne in mind that only purifiers handling approximately the same 
grade of middlings should blow into the same collector, or a chamber to 
which collectors are attached. In this way, not only is the desired cur¬ 
rent maintained in a uniform manner for each grade of stock, but the 
material collected is graded. For instance, it is proper and light to run 
machines which handle the first middlings—middlings, say, which will 
pass through a No. 3 or 4 cloth—into one collector, or a chamber fitted 
with collectors, and the machines which handle the coarser middlings 
into another chamber. Of course, where each machine has its own col¬ 
lector, th s principle is better carried out. The collections from mid¬ 
dlings which will pass through a No. o, 00 or 000 cloth will be red and 
thin, and, if the suction is properly cared for, there will be little which 
should not go to the feed. Particularly is this true of the very coarse 
middlings. As the middlings get finer, the stock becomes richer and 
may take a higher place in the mill, but very seldom or never higher 
than tailings. The material from the dust collectors is a natural tailings 
product, and there is a distinct relation between the dust collector stock 
and the material which will pass over the tail of the purifier. As we 
know, it is very branny in the case of the coarse machines, and whiter 
and richer in the case of the finer ones. 

The application of dust collectors in a mill maybe very broad. Their 

use extends wherever there is dust, and, with the facilities which they 

* 

afford for avoiding waste, their use may be very extensive. A mill has- 
been regarded as a place which is naturally dusty, where one cannot go> 
without being covered with dust and Hour. The collectors, in a meas¬ 
ure, set all this aside. A mill may be kept clean from garret to cellar. 
It is not possible to keep the grinding floor in good shape, or to keep 
the roll frames clean, without the use of such devices. The first and 
greatest benefit is derived from a connection with purifiers. The next 
benefit comes from their attachment to reduction machinery. In times 
such as these, where milling products are more nearly uniform as to 
quality, it is important that devices of this kind be used for the purpose 

(<5) 


GRADUAL RKDUCTION Mll.I.IN'G. 


226 

of reducing the cost of the Hour, which they do in the saving of material 
which would otherwise be wasted ; and, by the way, this is an amount not 
inconsiderable. A continual blowing of this material out of doors is a 
continual blowing to the four winds of that amount of money. When 
we remember that the waste which goes on in Hour mills at the present 
time will in the future represent, when saved, the larger portion of the 
profit, we cannot but see the efficiency of a dust collector as a saving 
agent. Dust is a large waste, and in collecting it we make a large sav¬ 
ing. In time, this saving and the cleanliness of the mill, as effected at 
the same time, will make an appreciable difference in the cost of insur¬ 
ance, and as our companies organize more particularly as to the carry¬ 
ing of mill risks, as they study the causes of fire and loss, they will realize 
the safety of the dust collector to such an extent as to demand their use 
in mills insured by those who consider these risks in a thoroughly intel¬ 
ligent manner. 







CHAPTER LX. 


THE SIZING OF MIDDI.INGS-A METHOD OF SIZING DESCRIBED-PURIFICA¬ 

TION OF SIZED MIDDLINGS—AUTOMATIC FEEDS ON SIZING ROLLS. 

The sizing of middlings was considered carefully in a preceding chap¬ 
ter. The literal meaning of the word sizing—bringing to a size, making 
uniform in size—implies more than is usually done in the operation 
known as sizing middlings. It would not do to say that the idea should 
be carried out to the full meaning of the word. To follow it a little 
farther than is done into the implied idea of the definition, would mean 
to more nearly purify the middlings than can be done in any other way. 
It has been said many times that sizing is necessary in purification, and 
in the same connection that no system of purification can be, in any 
sense, complete without the use of the sizings rolls. On the same prin¬ 
ciple that we have to break wheat into small pieces in order to purify 
it, middlings are purer after their reduction and separation by fol¬ 
lowing reels. The reduction of wheat by the corrugated rolls might, by 
straining a point, be called a wheat cleaning process, as it is wheat puri¬ 
fication, and the only way that wheat can be thoroughly cleaned is to 
break it into middlings. Middlings are made by gradual reduction. 
There is no condition in the problem which would suggest that any dif¬ 
ferent method be followed out in the reduction of the middlings. It 
takes out the flour and gives a chance to purify the remaining product 
in the course of a system arranged for the reduction and purification of 
that stock. 'The middl ngs, as they come from the wheat in the first 
place, are purer than the wheat itself, likewise the middlings which leave 
the sizing system, and finally, the Hour which comes from the purified 
middlings is purer than the middlings from which it was made. 

The full benefits of a system of gradual reduction will be realized 
when the full system of gradual reduction is introduced. While we have 
gradual reduction at one end of the mill—for instance on the breaks—- 
and a less gradual method on the other end—say with the middlings— 
we will be able to appreciate the former, which we have, but not the lat¬ 
ter, where we have it not. 


228 


GRADUAL REDUCTION MILLING. 

In another chapter is described a system of sizing and intermediate 
purification similar to the one above outlined, though somewhat more 
complete in detail. All of the middlings which would tail over a No. 7 
cloth were divided into seven grades for the purpose of purification, and 
a similar number of grades for sizing. After the sizing, and previous to 
their entering the reels, the number of grades was reduced to five for the 
purpose of repurification. Each grade of middlings of the original 
seven passed over two machines previous to sizing. The cut-off from 
each last machine was sent to the next coarser grade for purification 
with the middlings of that grade. The sizing commenced with coarsest 
middlings, and all those which passed through a No. 3 cloth and tailed 
over a No. 4 were purified on aspirator purifiers, and from thence passed 
on to the next grade for sizing, where the same operation was repeated 
in regard to their separation and purification, as well as their continu¬ 
ance to the next reduction. 

The finer middlings were purified on sieve machines of the ordinary 
form, and sized or reduced with the middlings of a corresponding grade. 
After each sizing, the middlings and flour which would pass through a 
No. 7 cloth were taken out, and the operation of purifying and sizing 
the larger middlings was continued until the middlings would pass through 
a No. 7 cloth. There were two short scalping reels after each sizing. 
They were used for dusting, grading and scalping the stock. At the 
tail of each reel there was material taken off to the tailings. This car¬ 
ries out the idea of the gradual reduction of middlings according to the 
ideas previously stated. 

The sketch here given is for a much less elaborate system of sizing. 
This plan would readily do for a mill of 200 barrels on soft wheat. The 
sizing here, in the first instance, is done on a double pair of rolls—mid¬ 
dlings from No. 1 to o, inclusive, going onto one side, and from No. 00 
to 000, inclusive, going onto the other. This grading makes it possible 
to do better work in sizing than when they all run together into the 
hopper, and in a mixed mass to the rolls. The sketch here given 
does not carry out the idea of the gradual reduction of middlings ex¬ 
cept in a crude way, though in away less crude than is ordinarily prac¬ 
ticed. All the Hour and middlings which pass through a No. 7 cloth on 
the first reel are dusted on the second, and the desirable portion of the 
stock, which passes through the No. 5 cloth on the end, is commonly re¬ 
garded as purified middlings. The product of the No. 1 cloth on the 


GRADUAL REDUCTION MILLING. 


229 


o\o O O 





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op 


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2*°SVZ\WaS 


U. 5 


fust 1 eel goes to a system of purifiers to be repurified, and from thence 
to the purified middlings. 

I he product of the No. 00 cloth goes to the second sizing rolls to be 
reduced. I his stock should pass over an aspirator, or, if possible, 

over an aspirating purifier before 
going to this set of rolls. The reel 
for the second sizings is clothed 
somewhat finer, the tail of the No. 2 
cloth going to the tailings. It will 
be noticed that there are two purifi¬ 
ers in connection with this sizing. 

One frequently meets with stock 
similar to the cut-ofts from these pu¬ 
rifiers, which are here designated as 
going to the third sizings rolls, which 
are too rich for tailings and too poor 
for middlings; they should go to an 
intermediate set of rolls. In the 
sizing of the middlings on the rolls 
is a good chance for the display of 
skill in grinding or setting rolls, as 
sizing cannot be properly called 
grinding. Where the grinding is too 
close, the middlings are sure to be 
flat and difficult to purify. On the 
other hand, if the grinding is too 
open, there will be a waste at the tail 
and the fine middlings will be red. 
The writer has known an automatic 
feed to be placed on sizing rolls. That is the worst thing which could 
possibly be done. If it were possible for such a feed to automatically 
set the rolls, it would not be so bad; but, as we have not arrived at that 
point yet, we will have to trust to the skill and judgment of those hand¬ 
ling the machines, rather than to an arbitrary feed. Where the auto¬ 
matic feed is used, the miller or grader cannot always be on hand to 
change the rolls as the feed changes, and, where that is not done, the 
grinding will be as irregular as the feed. An automatic feed may be a 
labor-saving device,, but it cannot be thought that it is a money-saving 








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fUR'u rt) 
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23 ° 


GRADUAL REDUCTION MILLING. 


arrangement. In the case of the sizings rolls, with its use, there will be 
flat middlings at one time, and shortly after a rich tail. Where the miller 
or grinder has to change the feed with his own hand, his attention is in¬ 
vited to the setting of the rolls to correspond therewith. 

In dropping the consideration of the generalities of this subject for the 
present, the writer is led to think of a question which has often been brought 
practically to his mind. It is why one mill is easier to run than another 
when the cause is not conspicuous. The fact of the reason not being ap¬ 
parent on casual examination does not indicate that it does not exist. A 
miller’s experience will bring him in connection with mills, one of which 
may run along nicely and smoothly, and another which will be causing 
general trouble, and, as implied before, without conspicuous reasons. 
One cause of these difficulties is in the improper proportioning of the 
machinery, and more particularly the elevators. We will say that in 
the mill all of the elevators are large enough for the work they are in¬ 
tended to do, and that none of them are too small. But perhaps two 
or three scattered through the mill are too large. Say in one of these 
a choke occurs; it is a natural thing, and at some times uncontrollable, 
that such an elevator will take all it can carry. Now, this being the 
case, it will give the next reel, roll or other machine a large bulk of 
stuff, which will in turn pass it to the next elevator, which, we will say, 
is the proper size for a mill of the capacity in which it is placed, but 
having to carry the stock given to it by a much larger elevator—one un¬ 
necessarily large—it in turn is choked. The same thing may be caused 
by feeding into a large elevator to the extent of its capacity, or if not 
to that extent, in excess of the capacity of the small elevator. Thus it 
is clear that an elevator which is too large may cause chokes, as well as 
one which is too small. It is a question of proportion. 


CHAPTER XLT. 


PURIFICATION FOR A IOO-BARREL MILI.—DESCRIPTION OF 


DIAGRAM—A 


SYSTEM OF GRADUAL 


R 


EDUCTION AND PURIFICATION OF MIDDLINGS. 


With this chapter is given a diagram of a system of purification for a 
small mill—say too barrels in twenty-four hours—and, as it is common 
to have a limited number of separations in a small mill, these limitations 
have been considered. We have shown on the diagram two sieve 
graders with aspirators attached, four sieve purifiers, two aspirating or 
gravity purifiers, two sets of smooth rolls and three reels. The mid¬ 
dlings which go to the shaking grader A are such as will tail over a No. 
9 cloth and pass through a No. ooo cloth. Thus we have middlings 
from No. 9 to 000 to purify. They are graded into five grades on shaker 
A , through Nos. 3, 1,0, 00 and 000 cloths. Those which go through 
the No. 3 cloth pass to sieve machines Nos. 1 and 2, which is shown on 
the drawing with the two upper lines for the sieve, and the two bottom 
lines with arrows for conveyors. The middlings which pass through Nos. 
1 and o cloth are each aspirated separately and then pass into a gravity 
separator or purifier of the Gray or Worner pattern, or perhaps one sim¬ 
ilar to the machine illustrated in a preceding chapter, which is reprinted 
in this chapter for the sake of illustration. On this machine, No. 3, 
the middlings are regraded into four grades through grits gauze Nos. 52, 
46, 42 and 36. No. 52 is equivalent to No. 2 bolting cloth, 46 to No. 
r; 42 is midway between Nos. 1 and o, and 36 equals No. o. The mid¬ 
dlings are thus graded into four grades on this machine, each grade fall¬ 
ing through an independent leg of the aspirator that has a distinct suction 
suited in force to each grade. The purified middlings pass through the 
opening H , as shown on the sectional cut, and the impurities pass out 
through the opening G. This cut shows two legs of the aspirator, 
whereas the diagram cut shows the machine complete with four legs. 
For convenience of illustration, and as is common with most machines 
of this kind, the impurities are shown as coming out of the side of the 
machine and passing off with the tailings. This opening, as said before, 
corresponds with the opening G on the sectional cut. On each machine 


23 2 


GRADUAL REDUCTION MILLING,. 


there are four grades of these impurities, varying in size and specific 
gravity according to the grading on the sieve above. The purified mid¬ 
dlings from this machine come out in four distinct streams and size 
from grade 2. 

The middlings which pass to purifier No. 4 are those which pass over 
the No. o cloth on the grader, and through the Nos. 00 and 000, each 
grade being aspirated separately as before, and thence to the purifier 
sieve to be graded over No. 32 grits gauze, a size which stands midway 
between Nos. o and 00 bolting cloth. No. 28 equals No. 00, No. 26 
stands between Nos. 00 and 000, and No. 22 equals No. 000. Thus 
these middlings are graded through Nos. 32, 28, 26 and 22 grits gauze. 

The purified middlings from this machine make up grade No. 3, and 
the impurities pass off with the tailings as before. 

To return to machines Nos. 1 and 2. It will be remembered that the 
middlings which go to these machines pass over a No. 9 cloth and 
through a No. 3. Thus we have middlings from No. 9 to 3 to take care 
of. This is a wider range of size than would be recommended in a mill 

more complete, but this will answer 
the purpose of illustrating a system 
which will be made more complete 
in a future chapter. Machine No. 
1 is clothed with Nos. 7, 5, 3 and 1 
cloths, and machine ±\ T o. 2 with Nos. 
8, 6, 4 and 3 cloths. There are two 
conveyors under each machine. The 
upper one in each runs to the head 
of the purifier, and the lower one to 
the tail, as indicated by the arrows. 
The tail of each machine goes with 
the tailings, as does the cut-off from the first machine. If it be neces¬ 
sary to take some tailings from this conveyor, as it probably would be, 
the tail of the sieve being clothed with No. 1 cloth, while the middlings 
to that machine pass through a No. 3, it can be done. In this way the 
middlings from this machine to No. 2 can be made reasonably clean, 
which will give the second machine a chance to do good work. It will be 
noticed that there are no finished or purified middlings taken from the 
first machine. I hey all go to the second; that is, all excepting the cut¬ 
off. Middlings from the upper conveyor of machine No. 2 make up one 
















2 33 


GRADUAL REDUCTION MILLING. 

grade of purified middlings. The product of the bottom conveyor, or 
cut-oft, would form what is called grade No. 4, which is an off grade of 
middlings not good enough to be reduced to patent flour. This disposi¬ 
tion will be considered later. 

Middlings of grade No. 1 may be regarded as purified and ready for 
reduction into flour. Middlings of grades No. 3 and 4 have had the im¬ 
purities of less specific gravity than the middlings themselves removed, 
but they stiil contain germ and middlings with adhering portions of bran 
and other impurities. This separation is made by the smooth iron rolls 
and the reels and separating devices which follow. This purification 



A 


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fil 

i/9 


process commences with grade No. 4, which is sized or broken on smooth 
iron rolls, from whence they pass into reel D , which is clothed with No. 
6 cloth at the head, No. 2 in the middle, and No. o at the tail. The 
No. o tail cloth fixes the setting of the sizing rolls for this grade of mid¬ 
dlings. It is the intention to have the largest middlings on this sizing 
uniform with grade No. 3; hence the smaller ones are taken through 
Nos. 6 and 2 cloths, the larger through No. o. The conveyors under 
this reel are arranged so that the undesirable portion going through the 
tail of No. o can go to the tailings rolls. This is done by closing slides 














































































































2 34 


CRADl'AI, REDUCTION .Ml I.LINO. 


at the tail of the upper conveyor, thus sending only the best middlings . 
of the larger size to grade Xo. 3. Middlings which pass through the 
No. 2 cloth, and the undesirable portion of No. 6, pass to grader B. 'The 
cleaner portion, which passes through No. 6, and contains the Hour and 
fine middlings made in sizing this grade, passes to reel E. It will be 
seen that the sizing of the fourth grade of middlings has in mind their 
reduction to a grade equivalent in size to grade No. 3, and at the same 
time the removal of the impurities which were the size of the original 
middlings. In sizing from Nos. 000 and 00 to Nos. 1 and o, the rolls 
will not be set so close as to make Hat middlings, their setting, as inti¬ 
mated before, being influenced by the tail of the No. o cloth of reel D , 
at the same time keeping the middlings which pass through this cloth 
round and sharp. 

We now have middlings of grade No. 3 to deal with. They are sized 
with reference to tail, product and cut-off of the No. 2 cloth on the tail 
of reel C, the product of this No. 2 cloth going to shaker B, and the 
tail and cut off thereof going to the tailings. The product of the No. 6 
cloth of this reel goes to reel E. It contains the Hour and fine mid¬ 
dlings made in sizing this grade of middlings. 

Reel E separates the Hour from the fine middlings made in sizing 
grades Nos. 3 and 4 of middlings. The head of this reel is clothed 
with Nos. 12 and 14, and the tail with No. 5. Perhaps it would have 
been better to have clothed this tail with No. 6, as that is the number 
through which the middlings originally passed; but, as they were then 
mixed with coarser middlings in reels D and C, they would bolt much 
sharper and freer than when by themselves in reel E. A No. 6 cloth 
on reel E would tail over gbod middlings which would pass through a 
No. 6 cloth with the stock of reels C and D. Leaving the clothing of 
reel E as it is, in event of the stock bolting through the tail of No. 5 
being thin and red, it could pass with the tail to the tailings rolls by 
closing up ? desired amount on the upper tail conveyor. The desirable 
portion of Hour, the product of Nos. 12 and 14, can be taken from the 
top conveyor as indicated. The cleaner portion of No. 6 and the cut¬ 
off of the Hour cloth pass off by means of the bottom conveyor as puri¬ 
fied middlings. These are the cleanest, brightest middlings in the mill. 
Their purity is owing to their purification in their original size as repre¬ 
sented by grades Nos. 3 and 4, and the subsequent purification by the 
sizing rolls and the following reels. 




GRADUAL REDUCTION MILLING. 


2 35 


It will be remembered that the impure product of the No. 6 cloth of 
reel D , together with that which goes .through the No. 2 cloth of the 
>ame reels and the cut-off of No. 6 cloth, and the product of the bottom 
conveyor under the No. 2 cloth of reel C, passes to shaker B. This 
shaker, or grader, though of smaller dimensions, is of the same design 
as grader A. This grader, it will be noticed, is clothed with Nos. 4, 3 
and 2 cloth. Each grade of middlings passes through an aspirator which 
is of the same construction as one leg of the purifier already described, 
the lighter impurities, as before, going with the tailings, and the products 
going to the sieve purifiers below. The middlings passing through the 
Nos. 3 and 4 cloth go to one machine, and those through the No. 2 
cloth to No. 5 purifier. The tail of No. 2 cloth on the grader goes to 
the tailings. The middlings which go through the No. 4 cloth have been 
dusted over a No. 6; thus this grade is in size from No. 6 to 5 inclu¬ 
sive. The machine which handles this grade of middlings and those 
which pass through the following No. 3 cloth, is clothed with Nos. 6, 5 
and 4, the tail of No. 4 going with the tailings, and the product of the 
upper conveyor, as purified middlings, to the middlings bin. The cut¬ 
off' represented by the product of the bottom conveyor goes with the 
middlings of grade flour. The tail of this machine over No. 4 cloth 
would be richer, perhaps, than desirable, but on general principles the 
tails and cut-aft' from the machines and reels, as represented in this dia¬ 
gram, run richer than they would were more elaborate arrangements 
provided for taking care of the various products. 

Machine No. 5 is clothed with Nos. 2, 3 and 1 cloth, the desirable por¬ 
tion on the upper conveyor going as before with purified middlings, and the 
cut-off and tail with the tailings. There are some who would say : “Why 
not put the two grades of middlings from this sieve B on one machine 
and then repurify them on the second?” In the first place, better work 
can be done by grading the middlings into a larger number of grades, 
and then purifying them each on one or two machines, than by lumping 
the grades and passing them over a larger number of machines. By the 
former method the suction can be adjusted so as to recognize smaller 
differences between the specific gravity of the middlings and the impu¬ 
rities. Of course, there is such a thing as carrying this too far, and the 
only difference the writer would suggest from the method represented, 
would be to place an extra machine under each No. 5 and 6, getting the 
benefit of the scalping and sieve action of the first machines, together 


236 


GRADUAL REDUCTION MILLING. 

with their suction, to be followed by the sieve action and stronger suc¬ 
tion of the second machine. <. 

The size of purifiers is entitled to more consideration than is generally 
given. For a mill of this size and equipment the machines would natur¬ 
ally be quite small. They should be of such a size that the quantity of 
middlings which passes over them should entirely cover the sieve. 'This 
can, in a measure, be regulated by the clothing, having a larger or smaller 
proportion of fine cloth at the head, according as the stream of mid¬ 
dlings is large or small. It is not possible to fix the size of the machines 
or the proportioning of the various numbers of cloth unless one knows 
the amount of middlings which will be made from a given quantity of 
wheat, which amount is regulated by the quality of the wheat as to its 
hardness or softness, and the quality of the grinding, each being vari¬ 
able. Quantities being equal, a machine which handles coarse mid¬ 
dlings should be smaller than one which handles fine middlings. In a 
gradual reduction roller mill there is a much larger proportion of coarse 
than fine middlings; therefore it is safe to make the machines for the 
different middlings of the same size, allowing the proportioning of the 
amounts of the various numbers of cloth to make up for the difference 
in volume and sieve capacity required. 

Reference was made to middlings of grade No. 4, which are not dis¬ 
posed of in the run of the material shown on the diagram. In a mill of 
this size and equipment, these middlings, which, as said before, are of a 
little oft' grade—not good enough for direct reduction into patent flour 
and too good for tailings—should pass through a set of smooth iron 
rolls, reducing them enough to alter the relative difference of size be- 
tween the good middlings and the impure stock. They should then go 
to a short reel, say four or five feet long, clothed with No. 4 or 5 cloth 
—4 for soft wheat and 5 for hard. The tail, and perhaps a cut-off 
from this reel, would go with the tailings, and the remaining product of 
the reel would pass into a flour reel clothed with flour numbers at the 
head, say Nos. 12 and 14, and No. 7 or 8 at the tail. The better por¬ 
tion of stock from this cloth and the cut-off from the flour cloth, would 
pass off and into the stock which goes to make up the purified fine mid¬ 
dlings. The cut-off and tail from the scalping cloth of the flour reel 
would go to the set of smooth rolls which handle the product of the tail¬ 
ings roll reel; that is, that portion which would pa«s through the scalp¬ 
ing cloth of that reel. 



GRADUAL REDUCTION MILLING. 


237 


The next step in purification would be in connection with a reduction 
to tlour, but will not be considered in this chapter. The reduction in 
the methods of purification has been gradual, and such reductions have 
been made on middlings of approximately the same size. It would be 
desirable to have this classification still closer, and to continue it through 
and as a part of the final methods of reduction, though it will not be 
possible in a mill of this size. It was intended to say something about 
a system of clothing, as applied to sieves and reels used as a part of the 
purification methods, but, as the meaning can be better illustrated by 
another diagram which is to follow, this will be reserved until that time, 
simply saying that such a method can be formulated and the formula 
used to the exclusion of all guess-work and experiments, the clothing of 
a machine or reel being a matter of foresight, with the certainty of a 
definite result. 


CHAPTER XLII. 


THE PURPOSES OF A DIAGRAM AND A DESCRIPTION THEREOF—A DIAGRAM 

WHICH IS TO HE USED FOR THE DEVELOPMENT OF THE IDEA OF GRADUAL 

REDUCTION AND PURIFICATION—A DESCRIPTION OF THIS DIAGRAM. 

With this chapter is given another diagram. It may be said that a 
diagram should be so drawn as not to need lengthy explanations. So 
far as the run of the stuff is concerned, this may be true, but merely 
knowing the run of the material does not give its purposes or intentions. 
One not only wants to know where the stuff goes, but why it goes here 
or there. So far as real knowledge goes, this is the valuable portion, if 
there is any. 

In this diagram are shown graders, purifiers of the sieve and suction 
form, air purifiers of the aspirator pattern, rolls and reels. It is the pur¬ 
pose of the writer to show that all alike are purifiers—that purification 
means purification by whatever means, and that such means are purifi¬ 
ers. There is a general understanding among millers that middlings are 
purified solely for the purpose of making patent Hour, and that if they 
cannot be purified to such an extent as to make them clean enough for 
such Hour, they need not be purified at all. This is limiting the use of 
purifiers. The purpose of milling in general is to make pure flour, and 
where that is not altogether possible, to come as near such perfection 
as possible. There is no exact or dividing line between patent and the 
best bakers’ or clear flour. Making good patent flour alone is not the 
end sought for in milling. Where middlings have not been made clean 
enough for pure or patent flour, they should be made as pure as possible 
for the bakers’ or clear flour. There is no good reason for not doing 
the best we can for middlings when they cannot be made clean enough 
for patent flour. It is as necessary and as much to the advantage of 
the miller that they should be subjected to such action under these cir¬ 
cumstances, as if they were going into the cleanest and best flour. 

In this diagram some of the poor stock is subjected to the action of 
the purifying devices for the purpose of making a better grade of clear 
or bakers’ flour than would be possible without such action. 



GRADUAL REDUCTION MI I.LING. 


2 39 


The diagram which is to be described in this chapter is more elaborate 
than the writer can expect to see put into actual practice. Its value is 
to be derived from the exposition of the principles involved; and it is 
from this one that all of the more simple diagrams are to be constructed, 
even when only three or four machines are to be used. 

There is a constant demand or incentive for improvement—advance¬ 
ment in everything. It has been shown through the experience of mill¬ 
ers that it is possible to make a certain proportion of pure Hour, and 
therefore the line of advancement in the quality of milling products is 
in the direction of a larger proportion of pure flour on one hand, or an 
improvement or advance in the purity of the lower grade on the other. 
It has been said before that in order to make a pure flour there must be a 
pure something else to begin with. Other things being equal, the purity 
of clear or bakers’ flour will be more nearly possible in proportion as 
the stock out of which it is made is pure. As the grades of stock 
approach purity, the flour will be proportionately pure. With this in 
view, it is easy to see that the improvement of the clear or bakers’ flour 
will be met by the purifiers, and the idea that the purifiers belong to 
the patent flour alone will be wiped out. Tailings from purifiers and 
the residuum from the various purifying devices are frequently sent in a 
conglomerate way to the smooth rolls, and the term tailings rolls stock 
has a wide, mixed and uncertain meaning. 

But to cut this general talk oft' short, we will go directly to the con¬ 
sideration of the diagram'. In the first place, the middlings are sup¬ 
posed to tail over No. 9 cloth, and go on to grader A, where they are 
divided into two grades through Nos. 56 and 22 grits cloth. The prod¬ 
uct of No. 56 goes to grader B , and that of No. 22 to grader C. No. 
22 being the coarsest scalping number, the tail of this grader goes to the 
sixth reduction. This arrangement would work all right when there 
were no holes or leaks in the break scalpers, but when the middlings 
come directly from the middlings scalpers, the product of such holes and 
leaks shows up on the graders. At the same time that it is not conven¬ 
ient or desirable to stop the mill for such small disorders, on the other 
hand it is not right to send the coarse break stock, which has found its 
way to this point from, say the third or fourth reduction, to this lower 
or sixth reduction. One way to arrange this is to aspirate this tail stock 
by means ot a strong suction, and in this way the heaviei 01 bieak stock 
which tails over can be sent to some suitable break, say the third or 


BREA K M/DS 






























































































































































































































































































































GRADUAL REDUCTION MILLING. 


241 


fourth. There is a very large proportion of light, fly-wing bran tailed 
off from this grader A. This is one good thing about a grading sieve— 
that the light, fine, fluffy stock is tailed off, while with a reel it is driven 
and forced through the cloth with the middlings, thus rendering the work 
of purification more difficult. After the stock is graded into two general 
grades in the manner described, it is subdivided on graders B and C. 
The former is clothed with Nos. 68, 60 and 58 grits cloth. The product 
of this grader is purified on purifiers of the ordinary form. The 
three numbers in their order, are equivalent to Nos. 6, 4 and 3 cloth. 
The product of the first division of this grader goes to machine No. 1, 
clothed with Nos. 70, 68 and 54. This grade of midtilings, it will be 
remembered, tailed over a No. 9 cloth. Thus we have middlings from 

No. 9 to 6 cloth to handle. The product of the first machine goes to 

% 

the second, no.finish being taken from this machine. The second ma¬ 
chine is clothed with No. 8 cloth and Nos. 70 and 68 grits gauze. Be¬ 
fore speaking of this machine it might have been well to have said that 
the tail and cut-off of the first machine goes to the coarse tailings grader. 
The product of the upper conveyor of the second machine is the finest 
grade of purified middlings, and the number of this grade, speaking with 
reference to their sizing—it being the intention to commence with the 
coarsest middlings and size down—is No. 6, as indicated by the number 
of the sizings reel immediately below on the diagram. The cut-off from 
this purifier goes to the first machine handling the next grade of mid¬ 
dlings. The purity of this stock will be influenced by the quality of the 
cut-off taken from the bottom conveyor of the No. i purifier. 

The first machine for the next grade of middlings is No. 3. The mid¬ 
dlings from this grade are those which will tail over No. 68 and pass 
through No. 60, that is in size from No. 4 to 6, cloth numbers. The 
disposition of the material going to the machines for this grade is the 
same as for the first grade. The product of the upper conveyor goes to 
machine No. 4, and that of the cut-off and tail, as indicated by the bot¬ 
tom conveyor, goes to the tailings. The upper conveyor of machine 
No. 4 makes the fifth grade of middlings, as indicated by the number of 
the sizings reel below. The tail of the machine and product of the 
bottom conveyor go with the third grade of ttnpurified middlings to ma¬ 
chine No. 5. This third grade of unpurified middlings is handled sub¬ 
stantially in the same manner as those before mentioned. This grade is the 
product of No. 56. The method of running the product of the bottom 


242 


GRADUAL REDUCTION MILLING. 


conveyor of the second machine of each grade to the first machine of the 
next grade has a two fold object; that is, to give this stock additional 
purification, and principally to be able to stock up the next machine. 
For example, the first machine of the second grade may have a stock 
too light to cover the sieve from head to tail, and only the middlings 
from its grading cloth above are taken, in which event it will be easy to 
throw over stock from the bottom conveyor of machine No. 2, which is 
the last machine of the first grade. In this way the tail cloth on all the 
machines can be properly covered. 

In a previous chapter it was said that a formula could be used to the 
exclusion of all guess work and experiments in the clothing of purifiers, 
the whole matter being arranged with reference to the certainty of a de¬ 
finite result. This is as good a place as any to explain what was meant. 
It will be remembered that the first grade of middlings those which 
will tail over a No. 9 cloth and pass through a No. 68. This will indi¬ 
cate the size of the middlings to be handled and aid in fixing the num¬ 
bers of cloth for this size of middlings. The first machine of each grade 
is clothed with a tail number slightly coarser than the cloth through 
which the middlings passed in coming to that machine. For instance, 
the first grade came through 68; the tail number for that grade is 64. 
The second grade comes through 60; the tail number on that machine 
is 56. The experience of millers in clothing machines shows the wis¬ 
dom of such a course. On most of the n achines the head number is 
slightly finer than the cloth through which the middlings of that grade 
originally passed. This proceeding holds up the middlings on the sieve 
so that there is no danger of losing a larger portion of the stock before 
it reaches the tail of the sieve, thus leaving part of the cloth bare. The 
grading number generally comes a little past the middle of the machine. 
Another reason for making the head numbers finer than the grader num¬ 
ber is that in all the machines after the first there are middlings coming 
to that machine from the next finer machine, which are finer than the 
middlings of the grade number. The second machine of each grade is 
clothed finer, head and tail, the tail number being the grading number 
and the head number the number of the next finer grade. For instance, 
the tail number of the bottom machine of the second grade is No. 60, 
which is also the grading number of this series of machines; that is, 
Nos. 3 and 4. The head number of this No. 4 machine is 68, which is 
the grading number for the next finer grade of middlings. 




GRADUAL REDUCTION MILLING. 


243 


To carry this illustration farther, notice the numbering of the machines 
under grader C. The middlings which go to this grader are those which 
tail over No. 56 and go through No. 22. The numbers on the sieves 
are arranged with reference to these grades. The machines which 
handle these grades are clothed as before with reference to the size of 
middlings as indicated by the number of the cloth over which they tail 
and the number through which they pass. The head number of the 
first machine for each grade of middlings is slightly finer than the num¬ 
ber for the next preceding grade. This is done to cover the contingency 
of the finer middlings being carried over. The tail number of such ma¬ 
chines is slightly coarser than the grading number. This is done be¬ 
cause there will be coarser middlings going through the grading cloth 
when impelled or forced by a body of larger and coarser middlings which 
go over to the next numbers or grades. 

In clothing the tail of the second machine of the series, it is possible 
to make its numbers the same as the grading numbers and yet preserve 
a light tail, as the middlings are cleaner and more free from impurities 
than when going on the first machine; thus they will more readily pass 
through the cloth. The head number of these second machines is gen¬ 
erally approximately near the next preceding grading number. The in¬ 
termediate space between the head and tail number is filled in with in¬ 
termediate numbers. The diagram will be followed out in the next 
chapter. 


CHAPTER XLIIL 


CONTINUATION OF DESCRIPTION OF LAST DIAGRAM-GRADUAL REDUCTION 

AND INTERMEDIATE PURIFICATION OF MIDDl INGS-CLOTHING OF THE 

REELS WITH REFERENCE TO THE SIZING— CLOTH INC OF THE PURIFIERS 
AS INFLUENCED BY THE RtDUCTIONS—PURPOSE OF THE GRADUAL RE¬ 
DUCTION OF MIDDLINGS—TAILINGS PURIFICATION—DISPOSITION OF 
PURIFIED MIDDLINGS. 

In the last chapter the middlings from grader B of purification diagram 
were traced as far as the sizing rolls. The middlings from grader C are 
graded through Nos. 52, 46, 36, 28 and 22, and are purified by aspirator 
purifiers, as described in a previous chapter. The handling of each 
grade is the same with reference to the purifiers, the middlings being 
graded into four grades on each machine, and the suction therefore 
graded to each size or specific gravity. Thus there are four products of 
middlings, and four of impurities, from each machine. The impurities 
go to the tailings grader and the middlings to the sizings rolls. The five 
grades of middlings from grader Care contracted into three grades after 
sizing, though the middlings from each machine run to separate roils for 
sizing. It is necessary that this division as to grades be preserved in 
sizing, in order that the rolls may do their work properly, such work be¬ 
ing impossible where the middlings going to the rolls are not uniform in 
size. This preservation of the different grades in sizing may be noticed 
by referring to the rolls in connection with the grader, where it will be 
seen that each grade is sized by itself, while the middlings from the No. 28 
and 22 cloth are spouted together after they are sized ; likewise the dis¬ 
tinct grades from Nos. 46 and 36. Accordingly, it will be seen that there 
are six grades of middlings as they go into the reels after sizing, and eight 
grades as they go to the sizing rolls. As it is unnecessary to follow out 
the course of the stock on each of the machines under grader C, it is 
well to go on with a description of the sizings, hesitating only to call at¬ 
tention to the aspirators under this grader, there being one such to each 
division. Thus the middlings are aspirated in a body before going to 




GRADUAL REDUCTION MILLING. 


2 45 


the purifiers below, the course of the stock at such points being clearly 
marked on the diagram. 

Each grade of middlings having passed through at least two purifiers, 
which contemplate the separation of the material detached from the 
middlings, which is either less in specific gravity or larger in size than 
the middlings, their purification as to the removal of adhering deleterious 
stock, and such as is of different structure or composition than the mid¬ 
dlings, remains to be considered. As previously described, this is done 
by the sizing rolls and the separating devices which follow. In the sys¬ 
tem of sizing diagramed, commencement is made with the coarsest 
middlings and the process continued until all the purified middlings will 
pass through a No. 7 cloth. The finer middlings of the different grades 
come in in their regular order as indicated by their size. The coarsest 
middlings, being those which come through the tail of grader C, are sized 
first. In this instance those which come through Nos. 22 and 28 are sized 
on rolls a and b, respectively, after which they pass to reel 1, clothed 
with Nos. 52 and 36. The setting of rolls a and b is influenced by this 
tail number, it being the purpose to tail over impure stock at this point. 
It will be noticed that the tail number on this reel corresponds to the 
grading number for the next finer grade of middlings; that is, No. 36. 
Thus middlings 28 and 22 are sized down so as to be uniform with those 
of the next grade. The middlings which pass through the No. 52 cloth go 
to the next lower reel. The desirable portion of that which goes through 
the No. 36 goes to purifier No. 17. A portion of the middlings which go 
through the tail of No. 36 may be too poor to go to this machine, in which 
event they can be sent with the tailings from this reel, by closing slides 
under such undesirable portion, which, as indicated by the conveyor, 
will start it in the proper direction. The middlings which go to machine 
No. 1 7 from this reel 1 are those which tail over a No. 52 and go through 
a No. 36 cloth. The numbers on that machine are from 48 to 34. Such 
head and tail numbers are slightly coarser than the head and tail num¬ 
bers on the reel. This purifier is of the aspirator pattern, and its prod¬ 
uct of middlings goes to roll C, which is of the series of rolls which 
handle the next finer grade of middlings than those out of which these 
were made. The product of the No. 52 cloth of reel 1 is dusted out on 
No. 70 in the next lower reel, the desirable portion of which product is sent 
to the series of reels below which remove the flour that is made in siz¬ 
ing. Next to the No. 70 cloth is No. 50, the middlings of this reel hav- 


246 


GRADUAL REDUCTION MILLING. 


ing originally passed through 52. This tail number being coarser, a part 
of the product near the tail of this cloth will go with the tailings. The 
other portion of the product of this cloth, which is a grade of middlings 
which will tail over No. 70 and pass through No. 50, goes to the grader D, 
which grades the fine middlings from the sizings. If the entire product 
from the No. 70 should not be clean enough to send to the reels which dust 
out the flour, the impure stock from the 70 can be dropped into the bot¬ 
tom conveyor under this reel and sent to the grader D , on which system 
it will be purified. The two coarsest grades of middlings, those which 
go through Nos. 28 and 22, having been sized down to the next finer 
grade, No. 36, it remains to take Nos. 36 and 46 and size down to grade 
52. This is done on the rolls c , d and <?, c taking the middlings from 
purifier No. 17, or those which will size down, and the rolls d from No. 
36, and e from No. 46. The stock from these rolls goes into reel 2, the 
head of which is clothed with No. 60 and the tail with No. 52, 52 represent¬ 
ing the next finer grade of middlings. The desirable product of No. 52 
which had tailed over No. 60, goes to purifier No. 18, to be purified before 
going to the next sizing. The product of the No. 60 of reel 2 goes into 
next lower reel under the same circumstances as does the correspond¬ 
ing stock on reel 1, into the reel below it. The head number of the 
reel below reel 2 is 70, in common with the same reel under 1 and 3, 
this being the number through which clean middlings and flour are taken. 
The tail number of these lower reels is influenced by the head number 
of each upper reel, being slightly coarser. The reason for its being 
coarser is that the lower reel does not have as sharp stock to handle as 
does the upper, and. for that reason, a slightly finer number on the upper 
reel will bolt as coarse as the slightly coarser number on the lower reel; 
and, in any event, if the tail cloth of the lower reels should yield poor 
material near its tail, it can be sent off with the tailings by closing slides 
under the conveyor, in number and position as indicated by the quality 
of the stock. The numbers on the purifiers intermediate between the 
sizings are influenced by the head and tail numbers of each of the upper 
reels which they follow. 'Hie head of reel 2 being 60, that on purifier 
No. 18 is 58, and the tail number of reel 2 being 52, the tail number of 
the corresponding purifier is 50. The head and tail number of each 
purifier is thus slightly coarser in each instance. The next sizing is from 
No. 52 to No. 56, as indicated by the tail number of the upper reel 
which bolts out the stock from the sizing, the general movement of the 


GRADUAL REDUCTION MILLING. 


247 


material having the same purpose as in the bolting of the previous siz¬ 
ings. For this reason it is not necessary to follow it out here. It may 
be well for the reader to notice the relation which the numbering of this 
reel and the following bears one part with another, and to the previous 
and following reductions. It was stated early in the description that it 
was the purpose to size these middlings so that all would pass through a 
No. 70 cloth, and it may be noticed now that all the numbers on the 
reels are drawing closer to this number. The head number of the upper 
reel of the sizing was 52; the head number of the third is 64. The tail 
number of the second reel of the third sizing is 60. In the fourth sizing 
the numbers come so close together that a smaller number of separations 
is required; consequently one reel does the work. This is true also of 
the fifth and sixth. 

Before going on with the sizings of the middlings from grader B, it 
may be well to call attention to the fact that the middlings from the first 
three sizings—those which tail over the No. 70 cloth of each of the bottom 
reels, which bolt out the stock from such sizing rolls and pass through 
the tail number of such reels—pass to grader D , which grades for a dis¬ 
tinct system of purifiers for these sizings middlings. The size rises from 
60 to 50, as indicated by the tail numbers of the bottom reel of each 
series of sizings reels. The three tail sizes on this grader are aspirated 
before going to the purifiers. The machines which come under this 
grader are arranged with the same purpose as to numbering and move¬ 
ment of stock as described for grader B. The stock from the finest 
middlings—that which comes through a No. 60—goes to the rolls which 
size No. 60 middlings from grader B , and the coarser middlings which 
come from grader D go under grader B , which sizes a corresponding 
stock. 

To go on with the sizing, commencing with the stock which leaves 
purifier No. 19, which was the intermediate purifier between the third 
and fourth sizings, it is easy to see that the purpose is the same as with 
the previous sizings; that is, to break the middlings down to the next 
size, or from 5 : h e tail number on reel 4, and the grad¬ 

ing number of the next finer middlings. The product of the No. 70 of 
this reel goes to reels marked G, H, /, as do also the product of Nos. 
70 and 8 of the fifth and sixth sizings. 

We have now followed out the sizing of the middlings from the coarsest 
to the finest, and brought them all to a uniform size; that is, so they will 


248 GRADUAL REDUCTION MILLING. 

tail over a Hour cloth and pass through a No. 70. This, as a bare fact, 
may not appear significant of anything extraordinary, but such a method 
is what gives their wonderful purity to the high grade flours of Hun¬ 
garian milling. By the method as ou.lined, the middlings are first puri¬ 
fied in their original size as they leave the graders, and, after being puri¬ 
fied in this form by the various machines, they pass to the smooth rolls, 
and by this means are sized down one grade at a time, gradually and 
carefully, until a uniform size is reached. Following the first three siz¬ 
ings, the coarser grade of middlings is purified by air purifiers, and the 
finer—those which will tail over a No. 70 cloth—by suction machines 
of the ordinary form, after having been previously graded on a sieve 
grader. The last sizing—that is, of the middlings which come through 
a No. 68—is bolted or scalped through a No. 8 cloth. This is done for 
the purpose of giving additional purity to the middlings which originally 
passed through No. 68. If these midd ings were bolted through a cloth 
uniform with those of the reels of the previous sizing, there would be so 
little work to be done by the sizing rolls that little additional purity 
would be added to this stock. If the numbering of this reel was made 
uniform with the others there would be mathematical uniformity as to 
the size of the stock, but it would mean irregularity and uncertainty as 
to the uniformity in quail y of the products. Such a course would be 
carrying a good rule too far. It would be sacrificing a principle for a 
rule. There is no place which will show the natural development of the 
necessary numbers on reels, scalpers and purifiers any more clearly than 
this sizing and purification system; and by such a system the proper set¬ 
ting of the rolls, as to their closeness, is clearly defined by the tails of the 
reels which immediately follow them. If such tails are lumpy and hard, 
they show that the rolls are too far apart; if flat and white, that they are 
too close together. Sizing too fast or with close set rolls makes flat, flaky 
middlings which cannot be purified. If middlings have been once flat¬ 
tened in this way, the purifier or roll can do little for them after¬ 
ward. The roundness and sharpness of the middlings as they leave the 
reels will show clearly that the reels are not too close. The same stock 
will show sharp, and at the same time red and foxy, if they are too far 
apart. If the sizing rolls are properly adjusted, the product of the reels 
will be round and bright at the same time that the tails are thick and 
red. This method of sizing and separation, together with purification 
between sizings, lies in the line of progress in the mills of the future. 






GRADUAL REDUCTION MILLING. 


249 


The stock which passes through the No. 70 cloth of the sizing reels, 
and which contains the fine middlings and flour, is bolted out on the 
three reels G, //and /, the tail of which reels goes to the tailings grad¬ 
ers. The Hour is taken off at the head through a No. 13 cloth on the 
first two reels, and No. 14 on the third. The product of Nos. 70 and 
68 is the middlings which are to be reduced to patent Hour. 

Coarse and fine tailings graders are shown in this diagram, but the 
tact that such stock is graded and passed through purifiers does not im¬ 
ply that there is an intention to make patent flour of it. It means that 
there will be a better grade of flour, of whatever kind, made after such 
a process than there would be if the purification were not attempted. 
As said before, purifiers should not necessarily imply the manufacture of 
patent flour. What they do imply is an improvement in the stock which 
they handle, no matter how low it may be in its original state. The 
stock which goes to the coarse tailings contains a large proportion of 
small, thin, soft bran and a small proportion of thin, nubby stock. The 
effect of a grading sieve will be to make a good separation. The coarse 
tailings grader is clothed with Nos. 64, 58, 40 and 22. The product of 
64 goes directly to the smooth rolls, and from the three remaining num¬ 
bers through the aspirators, and thence to smooth rolls. With this qual¬ 
ity of stock the aspirators can draw heavy enough to take out all of the 
light stock, leaving only the heaviest stock to be reduced. The entire 
product of the flour stock from this grader is bolted out on reels B and 
C. The fine tailings grader has little stock to handle from the part of 
the mill described by this diagram, as it handles only the tails from reels 
G , //and /. and the tails and cut-offs from the purifiers on grader D. 
But there are other places in the mill which would furnish more stock 
for this grader. A part of the stock which went to the coarse tailings 
grader might with equal justice have been sent to this grader. As can 
be seen, the clothing of this grader is 60 and 50, and there are under it 
four purifiers, two for each grade, the numbering of the cloths of which 
is influenced by the grading numbers and the reels from which such 
stocks came. The movement of the stock on these machines is identi¬ 
cal with those previously described under those graders. The product 
of each grading number, after passing through the purifiers, goes to a 
distinct pair of rolls, after the reduction of which the stock is united 
and bolted out on reels D and E. 


CHAPTER LXIV. 


PURIFICATION DIAGRAM FOR A 200-BARR EL MILL-CI.ASSI FICATION AND 

PURIFICATION OF STOCK—DESCRIPTION OF THE DIAGRAM. 

In the diagram which is given, a system similar to the more elaborate 
one described in the last chapter, is shown. It covers all the main points 
given in the larger and more elaborate diagram. We have shown one 
grading machine, six purifiers of the ordinary pattern, two aspirating puri¬ 
fiers of the Worner or Gray pattern, three single aspirators, three pairs of 
smooth rolls with their scalping reels, and two flour reels. The middlings 
are those which will tail over a No. 9 cloth and pass through a No. 000. 
It has, no doubt, occurred to some of the readers that this represents a 
wide range of sizes, even to put on a grading machine. This method 
had its origin earlier in the process of milling than the purification of the 
middlings, and, as it is not a vital question with reference to their puri¬ 
fication, it need not be considered here. 

As will be seen, the middlings are graded into six grades by the grad¬ 
ing machines, each grade being aspirated separately before going to the 
purifiers. The aspirating of the middlings at this point aids not only in 
their purification in the direct way of removing fibrous and other impu¬ 
rities, but it is an auxiliary method, in that it removes any remaining 
portions of flour or dust which may have remained after scalping, or 
which were made in the travel of the middlings subsequent to that 
process. 

After the middlings are graded into these six grades they are con¬ 
tracted, as to number, into three grades, the original larger number hav¬ 
ing been arranged for the purpose of giving a nicer distinction in the 
arrangement of the suction on the aspirators. If the bulk of middlings 
going through these aspirators represented varying sizes, and, conse¬ 
quently, a wide range as to specific gravity, the suction could only be 
arranged with reference to the lighter impurities of the lightest middlings 
in that stock. By arrangement into this larger number of grades, the 
suction can be more nearly adjusted so as to meet the exact difference 
between the middlings of each grade and the contained impurities. 


GRADUAL REDUCTION MILLING. 


251 


I'he first two grades coming from the grader and aspirator go each to 
a separate series of purifiers. The first is composed of Nos. 1 and 2, 
and the second of Nos. 3 and 4. The first machine is clothed with 
Nos. 8, 7, 6, 4 and 3, and the second with Nos. 8, 6 and 4. No finish 
is taken fiom the first machine, the desirable portion of the product be¬ 
ing sent to the seco;.d. The poorer part of the cut-off, if there be any 
on this first machine, goes to the tailings. Grade 4 of the purified mid¬ 
dlings, which is the product of the second machine, goes to the purified 
middlings bin. The middlings of the next grade are handled on ma¬ 
chines Nos. 3 and 4, the third machine being clothed with Nos. 4, 3, 2 and 



1, and the fourth with Nos. 4, 3 and 2. The travel of the stock on the 
third machine is relatively the same as on No. 1. This statement will 
apply to the fourth, with the exception that the product of purified mid¬ 
dlings in the latter instance goes to the third sizing rolls or to middlings of 
grade No. 3, which is the same. The product of the bottom conveyor 
under machines Nos. 2 and 4 goes to the next machine in each instance; 
that is, from machine No. 3 it goes to No. 4, and from No. 4 to No. 5. 

The products of Nos. 1, o, 00 and 000 of the grader, after being aspi¬ 
rated, are spouted together, and are then sent to the purifiers of the 
aspirator pattern, as previously described, when they are submitted to a 
second sieve action and graded again by the same numbers. This is 
done on machine No. 5. This operation is repeated on machine No. 6. 
The tail of each of these machines would go to the tailings. The im¬ 
purities drawn out from the middlings on each aspirator would also go 








































































































252 GRADUAL REDUCTION MILLING. 

to the tailings. The product of machine No. 6 is divided into two grades 
of middlings for sizing, grade No. 1 being composed of middlings Nos. 
00 and 000, and grade No. 2 of middlings from Nos. 1 and o. The 
sizing commences with grade No. 1, which is sized down to the next 
grade as represented by No. o. The product of No. 3 cloth of reel A 
goes to reel D. The desirable portion of the product of No. o goes to 
a single aspirator, shown at the tail of reel A. The undesirable portion 
of the product of No. o goes with the tail of that reel to the tailings, 
the separation being made by slides under the upper conveyor. Push¬ 
ing in slides under the upper conveyor is destined to direct the carrying 
of such material as is included by that slide, toward and with the tail of 
that reel. 

The product of No. o, after being aspirated, goes with grade No. 3. 
The impurities drawn therefrom in aspirating go to the tailings. The 
product of grade No. 2 is sized down to meet the next grade, as repre¬ 
sented by No. 2 cloth, and as indicated by the tail number of reel B. 
The general direction of the separations of reel B are the same as pre¬ 
viously indicated. The product of No. 3 goes to reel D as before; the 
tail and undesirable portion of the product of No. 2 goes to the tailings, 
and the desirable portion of the stock of this number goes through the 
aspirator and to grade No. 3. Grade 3 is handled substantially in the 
same way, excepting that the product of the aspirator goes to reel D 
instead of to another set of rolls. The setting of the various rolls is 
indicated by the tail numbers of the scalping reels which follow such 
rolls. The first grade is sized down to grade No. 2, which is represented 
by No. o, and the second grade to grade No. 3, which is represented by 
No. 2, and the third grade to grade No. 4, which is represented by No. 
4. The product of the heads of the first two reels under the rolls, and 
the entire product of the third, is sent to reels D and E, as indicated. 
This means that the entire product of clean stock of the sizings rolls 
goes to these reels, where they are dusted, and the better portion, which 
tails over a No 6 cloth, is sent to the purifiers 7 and 8. The product of 
the No. 6 cloth from reel E is taken up as purified middlings and sent to the 
bin. The tail of reel D and the undesirable portion of the No. 2 cloth at 
the tail goes to the tailings. The middlings which go to purifier No. 7 
are included with those which will tail over a No. 6 and pass through a 
No. 3 cloth, the tail number on reel D and of purifier No. 7 being 2, 
though the stock which goes to such numbers is that which has passed 


GRADUAL REDUCTION MILLING. 


2 55 


through a No. 3. Such numbers are so disposed that they will prevent 
the liability of waste of tailings over cloth when heavily loaded. The 
tails of purifiers 7 and 8 go to the tailings. The product of No. 8 goes to 
grade No. 4 of purified middlings, being uniform in size with that grade. 
Thus it will be seen that all the middlings are sized down to an approx¬ 
imately uniform grade. 



/ 


CHAPTER LXV. 

THE FINAL REDUCTION OF MIDDLINGS—MILLSTONE METHODS OF REDUC¬ 
TION IN HUNGARIAN MILLS-CLOTHING OF REELS FOR MIDDLINGS OF 

VARYING SIZE PREVIOUS TO REDUCTION—CLOTHING REELS FOR MID¬ 
DLINGS FROM HARD AND SOFT WHEAT-METHODS OF CLOTHING REELS 

FOR MIDDLINGS REDUCED BY BUHRS-METHOD OF CLOTHING REELS FOR 

MIDDLINGS REDUCED BY ROLLS—A COMBINATION METHOD OF REDUC¬ 
TION AND SEPARATION WHEREIN ROLLS AND MILLSTONES ARE USED. 

Having described the general principles of the purification of mid¬ 
dlings, as understood by the writer, a system which contemplates their 
gradual reduction and gradual and intermediate purification, it may be 
in order to say something about the final reduction of such middlings 
into flour. In the more complete diagram as given, all the middlings 
were reduced gradually, and after each reduction were purified until, in 
the course of such reduction, all could be passed through a No. 7 cloth. 
Then they were regarded as purified; that is, purified as far as possible 
by mechanical means which are now at hand. In any event, they were 
regarded as middlings which were in a condition for final reduction into 
flour. 

In Hungarian mills where the foregoing system of purification is in 
general use, the middlings, after they reach this stage of the process, are 
reduced gradually by buhrs. They are touched very lightly with smooth 
buhrs through three successive reductions, from each of which reduc¬ 
tions the highest grade of patent flour is taken off. They are not 
crushed or pulverized, but are granulated. The grinding is high rela¬ 
tively. Thus whatever impurities there may be remaining in the mid¬ 
dlings are not liable to be pulverized or disintegrated by the stones. 
The middlings particles are reduced while the impure particles 
may be tailed off from the reels. Grinding of this kind—that is, high 
grinding with smooth surfaces, is not the barbarous process which is 
usually assigned to the process of millstone reduction of middlings. It 
is barbarous when the grinding is close—when the buhrs are out of bal¬ 
ance or face. 







GRADUAL REDUCTION MILLING. 


'55 


As the previous chapters on purification have had to do more with the 
general principles and the development of those principles, we will 
not now consider the reduction of middlings in any other sense than 
that of principle. It will not be considered with reference to that of 
special sized mills, but will be adapted to mills of various capacities 
during some of the later chapters. 

In the diagrams which follow as illustrative of the means of reduc¬ 
tion and separation which may be used in connection with the methods 
illustrated in the previous chapters, it may be noticed that on all the 
reels there are scalping cloths, and it is well to say here that these num¬ 
bers cannot be fixed arbitrarily. They depend upon the system or 
method which may be carried out. If the middlings be reduced so that 
all will pass through a Xo. 7 cloth, some of the tail scalpers may be fine ; 
or if the wheat of which the middlings is made be very hard and brittle, 
in that case they may be fine also. Again, if the middlings are very 
soft, some of the scalpers should be made coarser. This explanation 
is given to indicate that there can be no arbitrary rules in that matter, 
and that conditions which vary require that the methods should vary as 
well. Take as an illustration, Fig. 1. If all the middlings had only 
been reduced so that the coarsest would pass through a No. 4 cloth, and 
if such middlings were made out of soft wheat, it might be found that 
the No. 8 cloth would be too fine; or that the grinding would have to 

be lower than would be desirable 


1ft* 


/ST MIDDLINGS 

REDUCED BY STONES 


12 

8 

-- 

—- 4 — -—- 

s 12 m 

/O 




in order to prevent waste, the 
method of middlings reduction, 
in this instance, being by mill¬ 
stones. Again, if the middlings 
had been reduced so they would 
all pass through a No. 6 or 7 
cloth previous to final reduction, 
it would be right and proper, if 
the middlings were quite hard, to 
use if possible a finer number for the first tail scalping cloth, or, 
if not that, to run a little more of the product of the No. 8 with the 
tailings, which would be entirely possible with the conveyor as arranged. 

Figs. 1 and 2 illustrate a method of clothing reels for the reduction of 
purified middlings by buhrs. In this instance Hour is taken on the first 
reel. If the mill were large enough to justify it, it would be well to use 


k 

5 


Fi*. 1. 




















256 


GRADUAL REDUCTION MILLING. 



2ND MIDDLINGS 
REDUCED BY STONES 


a scalper with the same number of cloth on it as shown for the tails of 
the first reels, which is No. 8. Fine middlings which have been reduced 
by the millstones do not contain such a large proportion of sharp mate¬ 
rial as to prevent them from flouring nicely immediately subsequent to 
reduction or to any scalping operation, though if it is entirely convenient, 
the scalping previous to the Hour separations would be somewhat of a 

help. The conveyor under the 
scalping cloth of this first reel is 
shown as running toward the tail. 
By closing slides from the tail for¬ 
ward under this conveyor it is 
possible to send any proportion 
of the tail product of the No. 8 
which may be desirable, to the 
tailings. The amount of such 
stock can be determined best by 
examining the quality of the material which would drop into the bottom 
conveyor, or the conveyor which carries stock to the bottom of the next 
reel. It is one of the nice things about the arrangements for setting 
conveyors side by side, that the stock may be conveniently examined as 
it comes from the slide, and in that 
manner it can be determined to a 


Fig. 2. 




1ST MIDDLINGS 
REDUCED BY ROLLS 



12 


m 



Fig. 3- 


nicety just what to do with the prod¬ 
uct of each fractional part of the 
reel. There will be times when a 
part of this No. 8 product of the ^ 
first reel, as shown in Fig. 1, would 
be quite red, and should then prop¬ 
erly be sent to the tailings. Aside 
from the fact that this stock is sent to the tailings, the advantage to be 
gained is the proportion of sharp material before the stock goes to the 
next reel. 

The product of the No. 9 on the second reel is second middlings, to¬ 
gether with the cut-off from the No. 14 cloth. The tail of the No. 9 
cloth is second dust middlings. The quality of this second dust mid¬ 
dlings can be regulated by the quality of the material sent to the tail¬ 
ings from the upper conveyor under the tail cloth of that reel. It will 
be seen that in this instance the product of second middlings are such 











































257 


GRADUAL REDUCTION MILLING. 


as will pass through a No. 9 cloth. . Middlings of this grade through this 
cloth can only be made by millstones under the circumstances above 
mentioned. Fr in rolls, the second middlings are always coarser. The 
next, which is Fig. 2, shows the reduction of the second middlings from 
the previous reduction, and, as shown, is by millstones. There is only 
one scalping cloth on this system, the tail of which goes to the tailings, 

and a certain small proportion of 



2ND MIDDLINGS 
REDUCED BY ROLLS 


12 


3 —liw this tail cloth to the dust middlings. 


-i^Ng s 


4 


/3 




16 


M?of The proportion-of such material 


taken out by this scalper and sent 

-*-direction indicated, wi 1 be 

^ ,Ds entirely owing to the purity of the 
middlings previous to their first re- 
Fi »- 4- duction by millstones and the care 

of the bolting arrangements of such reduced stock. Nos. 12, 14 and 
16 cloth are shown on the Dottom reel. The use of No 16 cloth is 
justified here from the fact that the 

p*. 1ST MIDDLINGS 

stock would probably be thin and the ^b:duced ey rolls 


12 


k 

§ 

5 


k 


12 


I* 


7 



material which goes through it will be 
quite as sharp as that which went 
through the No. 14 on the same 
reel. The cut-off and tail from this 
reel is first dust middlings, and at¬ 
tention is called again to the fact 
that the quality of these dust mid¬ 
dlings is entirely owing to the amount of poor material which is allowed 
to be taken off by the tail conveyor under the scalper. The attention 

to these scalping cloths and the 
conveyors under them is so im¬ 
portant, and exercises so great an 


Fig. 5- 



2ND MIDDLINGS 
REDUCED BY ROLLS 




influence over the quality of the 


~fjj j Jq product of the following reels, that 

frequent attention has been called 
to that fact and will be repeated in 
° s the description of nearly every 
figure which is to be given in the 
subsequent chapters. Figs. 3 and 4 indicate a method for the reduc¬ 
tion of middlings by rolls. The tail numbers, as said before, are to be 

(*7) 


Fig. 6. 









































GRADUAL REDUCTION MILLING. 


258 

determined entirely by the size of the middlings going to these rolls. It 
should be remembered that all the scalping numbers on Hour reels should 
be kept as fine as possible, so that they tail over enough of the impure 
stock, but not too much. The principles involved in bolting the stock 
which has been reduced by the rolls are the same as those described in 
the bolting of the stock by millstones. The second middlings from 
the reduction by rolls are somewhat coarser than those made by the 
millstones, the former having passed through No. 7 cloth and the latter 
through No. 9. Then again, the dust middlings from the second mid¬ 
dlings from ro ls are coarser than those from the millstones. No. 8 as 
compared with No. 9 illustrates the difference. 

Figs. 5 and 6 show a compromise between the reduction by rolls and 
that by millstones. In this case the first middlings are reduced by rolls 
and the second middlings by buhrs. This is an especially good system 
for small mills where it is not possible to gradually reduce and gradually 
purify the middlings as far as we would wish. It will be seen that the 
dust middlings are of the same size where they leave the last reel from 
Fig. 6 as they were from Fig. 2, where both reductions of the middlings 
were by millstones. It may be noticed that the questionable stock of 
the better grade which comes from the roller reduction is sent to the 
second dust middlings. 


CHAPTER XLVI. 


SMOOTH ROLLS AND THEIR PRACTICAL OPERATION-FEEDING OF SOFT 

STOCK-ARRANGEMENT FOR KEEPING SOFT STOCK OFF THE ROUS-THE 

TENSION SPRINGS-SPEED OF FEED ROLLS-RUNNING OF STOCK OVER 

THE ENDS OF ROLLS-SCRAPERS-ROLLS OUT OF LEVEL. 

Our “Journey Through ihe Mill” has brought us past the purification 
of the middlings. We have said so much in a general way about the 
use of smooth rolls, the theory of their working and all, that it will not 
be out of place to stop here to consider, in a more practical way, some 
of the features of smooth roll operations. 

The writer once received a letter asking for information in regard to 
the best mechanical device for an attachment to feed rolls which would 
aid in feeding soft stock. The writer of the letter said that he had always 
had trouble with the material going to some of the smooth rolls, and 
had tried a great many attachments, among which were vibrators, rakes, 
etc. It is not necessary to make any changes in the feed rolls as ordi¬ 
narily constructed. The whole trouble may be obviated in the bolting 
apparatus. It is common custom to run the flour cut-off and the tail of 
the reel to the next set of rolls. As far as the tail is concerned, this is 
all right. Flour cut-offs have no business on a smooth roll. Having 
been reduced to flour once—having passed through a flour cloth—farther 
reduction is not necessary. If any benefit could be realized by reducing 
this stock by itself, it causes trouble enough and harm enough because 
of the irregularity of the feed when it is mixed with other material, to 
more than overbalance the anticipated benefits. Furthermore, it is not 
good milling practice to try to reduce coarse and fine stock on the same 
rolls. Not alone because it will not feed regularly, but because it can 
not be uniformly reduced, even if it could be as regularly fed. As to 
the importance of such a feed, it may be said that no set of robs can 
possibly do regular work, and no reel or set of reels can make regular 
flour, when the rolls do not do regular, even grinding. It is essential, 
in order to reach the best results, that there be an even, thin stream of 
stock, and that its uniformity be preserved from one end to the other. 


■6o 


GRADUAL REDUCTION MILLING. 


There may be a slight increase or decrease in volume from time to time, 
and by correspondingly changing the set of the rolls, uniformity of prod¬ 
uct may be^ preserved; but let it begin to come through in lumps and in 
an irregular way, and the flour from the reel which bolts that stock is 
sure to drop down. Nearly every one knows this, and it is only written 
as a reiteration of a recognized but often neglected principle. It is fre¬ 
quently the things which we know very well that we so sadly neglect. 
This same thing, i. e., the regularity of roller feeds, is a thing which is 
sadly neglected by millers who are fully aware of the attending evils. 

To return to the original subject under consideration : It was said that 
the whole trouble of feeding soft stock on rolls might be obviated on a 
bolting apparatus, and that Hour cut-offs had no business on smooth 
rolls. Herewith is given a sketch which will illustrate a method of 

switching the Hour cut-offs around the 
rolls rather than into the roll hopper 
of the next roller reduction. 'Take 
the first reel, for instance. The tail 
is clothed with No. 14 cloth, the 
stock pass ng over which goes to 
rolls No. 2. The cut-off from roll 
reel No. 1, or the stock which is so 
frequently sent to rolls No. 2, is sent to roll reel No. 2. This virtually 
means that it has gone around the roll, rather than through it, and where 
reels do not occupy the position which is here shown, that is, one under 
the other, the same result may be accomplished by spouting the Hour 
cut-off into the elevator of the next roller reduction. It then goes into 
the reel which bolts the stock from that reduction. With the plan as 
here shown, there is always dusted stock smt to the next roller reduc¬ 
tion, and hence stock which feeds readily and without coaxing. Where 
this coaxing is necessary, it would take one man for every machine, and, 
as no miller could think of doing anything so absurd, he would do the 
other absurd thing and have an irregular feed; and if it was carried far 
enough in its irregularity to influence the general grade of the product 
of the mill, which, by the way, is very readily done, there would be an 
irregular Hour and an irregular market therefor. 

In a mill where the plant is large enough, it might be well to take 
some of the stock which represents the coarser particles of the flour 
cut-off and reduce it by itself. Where the mill is not laige enough to 



















GRADUAL REDUCTION MILLING. 


261 


justify this being done, it is well to do the next best thing possible—come 
as near the accurate grading as possible. 

1 here is a point in the reduction of soft stocks, more especially when 
soft wheat is used, where roller reduction does not appear to have much 
effect upon it. It is that point where the material begins to feel feath¬ 
ery and Hat. A centrifugal reel will help this out to a considerable ex¬ 
tent, but there is a point beyond which even this cannot go. It is then 
that we use the millstone, and the work h done. One of the many 
causes which lead to this condition of things is grinding too close in the 
first reductions on smooth rolls. Another point is in trying to grind too 
much on all of them, and, as said before, one of the causes is in the 
natural condition of the wheat. There appears to be a point, in some 
instances, beyond which a smooth roll will not go. 

'The tension spring on rolls is neglected in many mills, and often when 
not neglected it is wrongly used. There is a disposition on the part of 
many to set them up very tight. A miller once told the writer that the 
objection he had to a certain roller mill was that the hand wheel of the 
tension spring was not large enough. It was suggested that he make up 
the deficiency by the use of a 14-inch monkey wrench. He had a feed 
about a quarter of an inch thick running to his rolls, the rolls being set 
up as tight as he could get them, and the belts as tight as possible. All 
this was positively wrong. The tension spring should be set up as lightly 
as possible to do the work, and a smooth roll should not have so much 
work to do but that it can do it without flaking. The corrugated rolls 
should have no more to do than they will do without indication of over¬ 
work, such as a mushy appearance of the stock, flat middlings, large 
proportion of flour and badly lacerated bran. The tension spring should 
be adjusted to suit the work done by every machine. 

Another thing which will bear attention is the speed of the feed rolls. 
Often it will be found that while the stream of stock going to the rolls 
is he ivy and sluggish, it may be made thin and free in its movement by 
increasing the speed of the feed rolls. It is often seen where improve¬ 
ments may be made in this respect. It is not generally understood that 
a material change may often be made in this way. There is nothing so 
important in the reduction of the material in the mill as the proper feed¬ 
ing of the stock for the rolls, and at the same time it is one of the things 
which is very seriously neglected. The writer once heard a very clever 
illustration in regard to the effects of overfeeding the bran rolls. A 


262 


GEADUAI. REDUCTION Mil.RING. 

young man said that if one ran three thicknesses of paper through the 
bran rolls, the outer paper would be most seriously affected thereby, and 
that the middle one would be protected. This illustration was intended 
to convey the idea that where a heavy feed of stock was run to the rolls, 
there were certain particles that would not be affected as desired by 
their operation. 

In examining the tail of the reels which handle the stock from smooth 
rolls, one frequently finds stock which does not appear to have passed 
through the reel; on the contrary, it is as large and sharp as it was when 
it went into the hopper. Of course, this may occur because of the im¬ 
perfect action of the scrapers. This trouble is readily recognized, and 
is not for consideration here. It is possible for stock to pass over the 
feed rolls to the rolls themselves and yet not between them or through 
them, and still pass down into the lower hopper and from thence to the 
reel and over the tail without having been affected in the least by the 
rolls—not having passed between them, but rather, as it frequently does, 

g over the ends. This is not stock 

which falls near the ends of the rolls, 
^ but it will run out from a distance of 
several inches from each end. Roll 
builders frequently furnish sheet 
metal arrangements to fit down be¬ 
tween the rolls for the purpose of 
preventing this, but they soon get 
bent and out of shape and are worse 
than useless, because they are de¬ 
pended upon to do something which 
they do not. They invite confidence and soon betray it. 

'The best thing to use for this purpose is y^-inch hickory cut in the 
form indicated by A, and placed as A between the rolls C and D. It 
should rest on the roll half an inch from each end. The grain of the 
wood should run in the direction of F to F. Thus the ends will not be 
broken oft as they would with the grain running ciosswise. These 
pieces A should be set one at each end of the roll and connected by the 
pieces G. The top of the piece A , at which point the pieces G are let 
into it, should extend high enough so as to fit under the wood casing 
of the roll. If the casing touches this contrivance lightly, the fit between 
the rolls will always be a close one. The pieces H extend out from A 
































GRADUAL REDUCTION MILLING. 


263 


so as to prevent the latter from moving sidewise. It should be just long 
enough to nearly approach the sides of the wood roll casing. 

We would suggest that our miller friends look over their smooth rolls 
with a view of determining whether they are losing anything in the man¬ 
ner previously mentioned. It may be best determined by an examina¬ 
tion at the extreme ends of the roll—beyond the point where one usu¬ 
ally expects to find mill stock. 

The scrapers play a very important part as contributing to the success¬ 
ful operation of smooth rolls. This fact is noticed to such an extent by 
at least one firm that they are putting two scrapers on each roll. The 
failure of a scraper to do its work properly has the same effect on the 
quality of the work as does improper feeding. A great deal of time 
and trouble may be saved in starting new mills by carefully setting the 
scrapers. It is best that they should be taken out and carefully dressed 
with a file and then set back, after which they should be adjusted so 
nicely that they will hold a piece of paper tight to the rolls throughout 
their entire length. If this work is done conscien iously, there will be 
little or no trouble from this source, and there will be a great deal less 
poor Hour made at the outset than is common. Smooth rolls cannot do 
good work unless the scrapers do their work completely and as intended. 

Rolls being out of level causes trouble with the Hour as well as with 
the final finish. By being out of level is meant that they are not in the 
same horizontal plane. This is very injurious to the rolls themselves, 
as the point of contact is at a smaller point or for only a small portion 
of the rolls, and wears them unevenly and gives a concave surface to 
each. The grinding cannot be in any degree satisfactory or complete, 
and, as implied before, the finish of the mill cannot but be extravagant 
and wasteful. A very good way to do, especially in starting up a new 
mill, is to first level the rolls after the belts are put on, and then, after 
they have been run awhile empty, and immediately before putting on 
feed, to go over them again, and after they have been run a week or 
thereabouts, to go over them once more, and regularly thereafter about 
once in two weeks. A miller will notice each time that some ol the 
rolls are out of level. This fact should prompt careful attention and an 
estimate ot the attending evils. 


CHAPTER XLVII. 


TAILINGS-THF REDUCTION OF TAILINGS-ASPIRATING TAILINGS-GRAD¬ 

ING OF TAILINGS. 

Having in mind all that has been said about middlings and the reduc¬ 
tion of the various stocks by rolls, it is a natural thing to take up the 
tailings. 

This word tailings has a wide, mixed and uncertain meaning in mill¬ 
ing. The hopper of the tailings rolls is a kind of a mill cesspool in 
many instances. It has everything run into it which has no other regu¬ 
lar assignment. With this same stock is frequently sent the cut-off from 
the last machine. Now there is with this material the best middlings in 
the mill, and, at the same time, the worst. In the reduction of the 
mass by smooth rolls, the flour product is seriously contaminated If 
there is nothing better to do with a particular kind of material, or if 
one is at a loss to know what to do, more often than otherwise he sends 
this stock to the tailings rolls. In small mills this sort of thing is de¬ 
manded; nothing else can be done. But there are other mills where 
this is done, but without the necessity or mitigating circumstances. 
Where it is possible, where the mill is large enough for two sets of tailings 
rolls, the stock should be graded so that one set would get the fine tail¬ 
ings and the other the coarse. It is not imperative in this case that 
there should be separate bolting arrangements for each grade of mate¬ 
rial. This separation on the rolls is made so that the grinding can be 
more perfectly done. It is well known that the mixture of coarse and 
fine stocks in reduction is fatal to the best work. In small mills, where 
separation is out of the question, the stock has to be ground together 
unless it is divided and ground at different times, which is not an ac¬ 
cepted method. At times the coarse and fine stock is spouted into the 
hopper through different spouts, this being done as a matter of conven¬ 
ience in spouting, and not with any particular method in mind. In this 
way, the fine part of the stock would go in at one end of the roll and the 
coarse at the other. This not only makes bad grinding, but is also very 
uncertain, and generally very unsatisfactory. Where coarse and fine 


GRADUAL REDUCTION MILT.ING. 


265 


tailings have to be reduced together, it would be well to mix the stock. 
The necessity for even grading in the reduction of stocks may be said 
to be of still greater importance, as applied to the smooth roll reduc¬ 
tions, than to the first break by corrugated rolls. The reason for this 
cannot be said to be in the rolls themselves, but rather in the character 
of the stock. Taking the tailings stock as an instance, it is easy to see 
that there is a greater difference, more of an unevenness in the size of the 
various pieces, than there is in the wheat of the first break stock; and 
hence more of a reason for grading in order to secure the full benefits of 
a reduction. 

Where it is possible to divide the stock, as suggested, on two sets of 
rolls, and then run into the same bolting apparatus, the Hour will be 
much better than if reduced on a single set of rolls. A more conspic¬ 
uous reason for this division is the quality of the finish; but because of 
its being conspicuous is no reason for its being more important than the 
other. The tailings rolls, it should be remembered, are intended to per¬ 
form the office of purification, as well as of reduction into flour, or the 
finishing of a part of the stock for feed. This being so, it is important 
that each granule should be subjected to the same purifying and discrim¬ 
inating influence. Each granule should be touched by the rolls in an 

4 

approximately uniform manner; hence the division of the coarse and 
fine stocks. A uniform action is necessary for a uniform result. With 
particular reference to the quality of the flour, it is necessary that no 
unreduced particles should go into the reel, or, rather, none of the par¬ 
ticles which have not been influenced by the rolls. The reasons for 
this, it will be remembered, were given in a previous chapter. 

The accompanying sketch illustrates one method of clothing the reels 
for the tailings, together with the distribution of the new grades of stock, 

brought about by its reduction. The 
stock is scalped on Nos. 7 and 2 
cloih, the product of the No. 7 go¬ 
ing into the flour reel below, and the 
undesirable portion at or near the 
tail of No. 7, and that which goes 
through the No. 2, to the last reduc¬ 
tion of the dust middlings. It would be preferable if there were three 
such reductions, and this stock went in with the third; or, better yet, if 
the mill were large enough to justify it, to a second reduction of the 







266 


GRADUAL REDUCTION AMI.I.1NG. 


tailings, in which event the first reduction need not be so severe. The 
second reel in the diagram given is clothed with Nos. 12, 13 and 14, 
and the tail with No. 6 cloth. It might have been said that the tail of 
the first reel goes to the bran duster. The tail of the second reel goes 
to the red-dog rolls. I r it is too rich, all that remains to be done is to 
open slides near the tail of the No. 7 cloth above, so as to throw more 
stock into the bottom conveyor under the first reel. This would reduce 

i 

the proportion of sharp material in the bottom reel, make the flour bet¬ 
ter, and the tail lighter and poorer. 

In the tailings is a large amount of soft, fluffy stock, which comes 
from the aspirators and the tails of the machines, together with other 
material which gives it place as tailings. A good thing to do with all 
this stock previous to reduction would be to run the entire body of the 
material over a grader, and then through aspirators to take this fluffy 
material out and put it into the feed. This could be readily done in 
such a way as to greatly improve the quality of the tailings, and at the 
same time not run anything into the feed which does not belong there. 
Aspirators can be made to be very sensitive, and to make very nice dis¬ 
criminations in the separations. The grading of the tailings would be 
done for the purpose of being able to aspirate the stock economic¬ 
ally. In this way the currents of air could be adjusted according to the 
specific gravity of the contained impurities. 

One of the bad things which is frequently seen in the operation of a 
mill is the sending of tailings from the coarse middlings purifiers to rolls 
without aspirating. It is one of the simplest things imaginable to aspi¬ 
rate this stock and almost entirely remove this fibrous and damaging 
material. A prominent millbuilder said that one reason why this stock 
was not more universally aspirated, or purified, which in effect means 
the same thing, was that to the eye the middlings did not look much 
better after being aspirated than before, this being accounted lor by the 
fact that there are large particles of middlings with adhering portions of 
bran. Thus the middlings could not look white. In sizing middlings 
this bran is not materially disturbed, while the flour and middlings por¬ 
tion is broken and separated therefrom. There have been published in 
connection with this work descriptions of aspirators which are in every 
way suitable for this purpose. They are among the simplest, most inex¬ 
pensive and most efficient machines which can be placed in the mill. 
If the coarse middlings are aspirated before they go to the purifiers. 






GRADUAL REDUCTION .MILLING. 


267 


coarse middlings purifiers themselves will he so materially aided in their 
work as to reduce the number of machines needed to purify the mid¬ 
dlings of the mill. These aspirators may be set in any place, and con¬ 
nected with a suction fan conveniently located. A fan of proper size 
may be made to answer for a large number of aspirators. Another 
use to which these machines may be put is in the aspiration of stock 
which goes to the tailings rolls. The use of this device will lead to the 
improvement of the work of every mill in which they are placed. It is a 
device which has been neglected. In it there is the way open for simple 
and inexpensive improvement. 


CHAPTER XLVI 11 . 


LOW GRADE STOCK—GRADING OF LOW GRADE STOCK-CENTRIFUGAL REELS 

FOR HANDLING LOW GRADE—THE BRAN DUSTER—RELATION OF LOW 
GRADE REDUCTIONS TO THE YIELD-USE OF SCALPING REELS WITH REF¬ 

ERENCE TO THE REDUCTION OF YIELD. 

The methods of handling low grade stock at the tail end of the mill 
have received very little attention. Most that has been said has been 
in regard to the higher grades. Percentages of low grade Hour and other 
general features have been talked about, but the details have not been 
looked into. In following out a diagram, or in doing the same thing in 
a more practical way—following out the run of the stuff in a mill—we see 
material of varying qualities going to the red-dog bin. It may all be of 
low grade color and character, but it will be in different forms in varying 
stages of completeness in its reduction, and in different sizes as to the 
particles. We all know that uniformity is desirable in any reduction of 
any grade of stock. Different qualities may invite different manipula¬ 
tion. Where there is this difference, anything which is exactly right for 
one grade is exactly wrong for another. There can no more be com¬ 
promise and still exact justice to all alike in this instance than there can 
be in other things. A compromise always suggests the idea of injustice, 
and frequently to all alike. It means merely the best thing which can 
be done under the circumstances. Put when we come to the point of 
suggesting what is right and proper in the case of the treatment of the 
red-dog stock, we run against a common obstacle, which is the size of 
the plant, and as by far the larger proportion of mills are so arranged 
as to be influenced by the limitation here implied, it remains to give this 
subject such consideration as this condition will warrant. 

On the above basis it will be recommended that the miller who in the 
future buys rolls for the purpose of reducing his red-dog, should, in the 
case of his having a small mill, buy two small pairs instead of one long 
pair. In this way he can get the red-dog material into two grades— 
coarse and fine—and thus do justice in the reduction to each kind of 
material. For the purpose of realizing on this principle a little further, 



GRADUAL REDUCTION MILLING. 


269 


it would be a good thing to scalp the coarse grade of stock by itself, 
before sending it with the general body of reduced red-dog material to 
be scalped and bolted finally. This may be done on a common form 
of centrifugal reel, a cheap variety of which is made by having a sta¬ 
tionary reel with revolving wings* set spirally. If it is possible for eco¬ 
nomical reasons, this reel might be set under the roll and the product 
could be run into the common red-dog chop elevator and the tail pre¬ 
sumably into an elevator which leads to the bran duster. It is not 
always possible to arrange this thing mechanically. Such a method 
of aspiration makes the general bulk of reduced red-dog material 
all of the same character, and hence it is in a better condition to be 
treated satisfactorily and with the assurance that there are no limited 
conditions as to the excellence of the work in the character of the stock 
itself. From the elevator it would be well to run this stock to a centri¬ 
fugal reel clothed with Nos. 8 and 9 cloth, a product of which is run 
into another centrifugal reel clothed with proper Hour numbers—say 
Nos. 12 and 14. There will be one grade of feed from the tail of 
the upper reel and another one from the tail of the lower one. If this 
is the last reduction in a mill, as it is fair to presume that it is, this can 
not be anything else than feed, and can be only so treated. As has been 
said before, if this stock is too rich for feed, further milling is suggested, 
which can only be done by additions to the plant. This will pay as 
long as the flour produced exceeds the value of the feed, taking into 
consideration the question of the additional cost of manufacture by such 
methods. 

One thing to do with the tails of the reels mentioned, is to run them 
through a vigorous agitator or bran duster of some kind and bolt out the 
product on a centrifugal reel. This is a make-shift, however. One very 
good reason for using centrifugal reels at this stage of the milling is that 
a large proportion of the material which goes to make up the red-dog 
stuff in its legitimate state of thinness, in quality is soft and flaky, or 
feathery, and the principle of the centrifugal reel is such that it will 
make the most of these unfavorable conditions. Furthermore, the cen¬ 
trifugal reel can separate or bolt this material when it is softer, than can 
any other reel. As has been said before, the softer one can bolt any 
material, consistent with economy, the whiter, cleaner Hour will he get. 
In lieu of the lack of complete methods for the reduction of the red- 
dog, and taking into consideration the disproportionate size of the plant 


270 


(JRADUAI. REDTCTION MILLING. 


in this part of the mill which would be required to make it complete, 
and again, considering the cost of manufacturing this low grade material 
with reference to the final price of the product, it may be said to be al¬ 
lowable or possibly desirable to use more vigorous means in its reduc- 

# 

tion and separation than would be desirable or profitable with other 
higher and more valuable grades of stock. Hence the mention of the 
use of the bran duster or other vigorous disintegrators for the tails of the 
red dog reels. The quantity of such stock is not large, and the propor¬ 
tion of flour therein is small, so that when we consider that the previous 
milling and grinding have been well done, there are not many cases 
where the rolls are large enough to justify continued handling. 

The treatment of the material from the bran duster has been here 
outlined. Where the course before mentioned with reference to the 
scalping of the bran from the last reduction of the wheat is carried out, 
there is little benefit to be gained by running it through a duster : yet it 
is a safe thing to do. One thing which is frequently neglected is to run 
the tail of the red-dog through such a machine. This is more important 
than the bran, and, where both are not possible, it would be well to let 
the latter go without such an operation and choose the former for dust¬ 
ing. The product thereof should be bolted out by a centrifugal. The 
proportion of stock to the amount of flour realized is larger in red-dog 
feed than is any other stock in the mill. 

The low grade end of a mill is often and carelessly regarded as being 
the only place to which one must look in order to get a good yield. 
It is said: “We must clean our feed, and we do it with this low grade 
machinery.” The mistake in this thing is that it is a too narrow view. 
It should be broad enough to cover the whole mill. A good yield can 
not be made without good finishing machinery, but if a sacrifice has to 
be made at either end of the mill, it should be done here. As a matter 
of business, such a sacrifice should not be made in any case. If the 
capacity of the mill is such that the owner cannot command the means 
to finish up reasonably well, ordinary prudence would suggest that he 
cut down the grinding capacity. 

We see mills operating under varying conditions. We see those that 
are thoroughly well equipped, and again others whose means for making 
good and cheap flour are meagre indeed. In the natural movement of 
things it will be found that the latter mills will have to step out or step 
up—they will be forced out of business, or will be forced to add to their 






GRADUAL REDUCTION MILLING. 


271 


equipment. lime was when there were only a few mills which made a 
very high grade of Hour; now there are many. There are very few mills 
now which are making very cheap Hour. As time moves on there will 
be many more. The mills will come more closely together on the ques¬ 
tion of cost, as they have on the question of quality. This element of 
cheapness will be a more forcible one than the original one of quality, 
because, when the latter was the great point, the demand for Hour was 
much greater than it is now. Everything which was made could be 
sold at a fair price. Now the producers are in the ascendency, and the 
buyers of Hour can demand, in a strong way, cheap goods. Thus com¬ 
petition will be to make the cheapest Hour, and, as the milling capacity 
is excessive, those who can make it cheapest can run their mills, and 
those who cannot must Stand idle. 

This condition of things has a bearing on the mechanics and upon the 
system of milling. It demands that all that pertains to the usual oper¬ 
ations be considered as to the quality of the work and as imperatively 
as to its cost. A great deal too much dependence is put upon the low 
grade machinery, in order to bring the yield down. The whole mill— 
every piece of machinery in it—has to do with the yield. We have to 
begin with the cleaning of the wheat, and then keep in mind the reduc¬ 
tions, one by one, remembering that any stock which is carried over 
from one reduction to the next adds just that much to the work of all 
machinery which follows. If any of that stock which is carried over 
ought to have been taken out rather than reduced with other material 
with which it does not belong, it should be known that it will, in pro¬ 
portion to its amount and quality, affect the yield. For instance, say 
that the breqk scalper is too short, or that it is clothed too fine, or gets 
filled up in a way to influence its capacity, it is apparent that the Hour 
or middlings which should have gone through the cloth will pass over to 
impede the action of the reduction machinery, and in the same degree 
ultimately affect the yield, and as well the quality of the Hour. Take 
another case of the lighter or softer stocks. If Hour which should have 
been taken out on the bolts be carried over to the smooth rolls, it is ap¬ 
parent that their feeding will be interfered with and that at the same 
time the stock will be increased in volume and made more difficult of 
reduction. This is a very common source of trouble, made necessary by 
the arrangement of the separations. Say that the coarse material fob 


272 


GRADUAL REDUCTION MILLING. 



lowing a reduction be not separated from it before beginning to take oft 
flour in the flour reels, it will then be found that it is necessary to send 
quite a proportion of flour with the cut-offs or tails in order to prevent 
the regular Hour product which goes to the packers from being specky. 
The accompanying sketch will illustrate this latter point. Say that a 
certain grade of stock be sent into ihe reel in Fig. i. It will be found 

that, owing to the coarse material 
going directly into this flour reel, 
there will be a large volume of 
cut-off, in consequence of the 
Hour beirg spt-cky, and it will be 
so sharp that the flour will have 
to be r dwced again. Very often 
this operation is repeated on the 
next reduction. Thus it will be noticed that only a comparatively small 
portion of the flour made at each reduction is sent to the packer, and 
stock winch has been reduced to the fineness of Hour is sent, because it 
contains objectionable stock, to the rolls to be reduced time after time. 
It is easily seen what effect this sort of thing will have on the yield, 
'fhe arrangement shown by Fig. 

2 provides for all this. It will be ^ 
noticed that a scalper is provided 
and that it is clothed with No. 8 
cloth, though this number would 
depend entirely upon the mate¬ 
rial going into the reel. 

It is desirable that the stock 
which goes into the bottom reel 
should be as soft as possible to 
bolt without the use of wipers. 

In this \\ay a larger proportion of 
coarse Hour cloth can be used, 
and the flour will be finer and 
whiter than on the finer cloth in Fig. i. There wiil be a very small pro¬ 
portion of cut-oft, if the scalping number is selected properly. The tail 
from both reels in Fig. 2 will be thoroughly dusted. Thus the rolls will 
have to handle only such material as is best suited to them; that is, stock 



Fi. 



















GRADUAL RLDUCTION MILLING. 


273 


which is sharp and entirely free from flour. It will feed perfectly; 
and, again, the volume will be smaller than in the other instance. It 
takes a smaller number of rolls to accomplish a better result with this 
system. This same principle, in one form or another, can be carried 
entirely through the mill. It always furnishes dust stock to the rolls, the 
same as to the purifier. 


CHAPTER XI.IX. 


SIZE OF MILES—RELATION OF SIZE TO THE NUMBER OF REDUCTIONS— 

NUMBER OF REDUCTIONS FOR A SIX-BREAK MILL—CLASSIFICATION AND 

SUB-CLASSIFICATION OF REDUCTION AND SEPARATION. 

As a general thing, any great difference in capacity between two mills 
implies a difference in the number of separations as well. In the smaller 
mills, only the greatest differences in the qualities of the various products 
are recognized in the classification of the material previous to its reduc¬ 
tion or separation. In a larger mill, where the volume of stock is heavy 
and where the plant is not proportionately greater in cost than in a small 
mill, the classifications can be more numerous, as would naturally be 
suggested by the various differences in the stocks to be handled. It is 
obvious that as large a number of classifications cannot be made in a 
mill which is to make ioo barrels of flour as in one which makes 500, 
and there will be finer, closer differences recognized in the material in 
planning a 1,000-barrel mill than there would be in a 500-barrel mill. 
This statement is made looking at it from a commercial standpoint. 
Looking at it mechanically, it is altogether possible to make a 100-bar- 
rel mill which would be as complete and maintain as exact and fine dif¬ 
ferences in the number of separations, and, as would be suggested thereby, 
an equally large number of the various milling devices, and as complete 
an equipment generally as the best 1,000-barrel mill. But such a mill 
would be a commercial absurdity. In this mill there would be required 
almost as many purifiers, though smaller in size than in a larger one; 
quite as many reductions, though not as many rolls, and in many cases 
as many reels for handling a small volume of stock as would be required 
to handle a larger volume. For example, a certain number of separa¬ 
tions may involve the use of two, three, or four reels, whether the vol¬ 
ume of stock be large or small. In the small mill the reels could be 
smaller, but the cost would not be proportionately less. The difference 
that there would be in the cost of two such mills would be brought 
about, first, by the size of the various machines, and, as we all know, 
the difference in cost is not as their size; second, in the small mill there 


275 


GRADUAL REDUCTION MILLING. 

would not l>e the necessity for the division of stock as to volume, as 
suggested by the capacity of the various machines on which this stock 
is to be handled. But a small mill of this kind could not be useful in a 
business way. It would bear about the same relation to a business un¬ 
dertaking that a working model does to the machine it is intended to 
illustrate. The small mills embody the general principles of milling as 
carried on in the larger mills. Where there are a very large number of 
classifications in the latter, with only minute differences as a distinction, 
in the small mills a number of these classifications are lumped—handled 
together—and thus the more elaborate system is simplified. 

In a former chapter another condition of things in connection with 
these smaller mills was mentioned. In speaking of the higher quality 
of low grade Hour which has been coming into market, it was suggested 
that it might be the result of incomplete roller milling; that is, unfinished 
milling. There is one end of the mill left out. In the desire for cheap 
mills and at the same time roller mills, something has to be omitted, 
and it is the tail end of the mill; and instead of making low grade Hour, 
it is thrown into the feed pile. But such deficiencies are easily reme¬ 
died by the addition of a few more reductions and the attending sepa¬ 
rating machinery. 

Continuing in the line of the above subject, it may be of interest to 
consider the smallest number of classifications possible in a roller mill 
with six breaks. In any mill there will be the Hour and the feed. 
These may be called the results—the reductions and separations with 
these results in view, the method, which is the interesting point. 

To commence with the break* of the wheat, there are the low grade 
flours and fine stock from the first break. Then there is the middlings, 
which can be sent with the other middlings to be purified. The second, 
third, fourth and fifth breaks yield a product from their scalpers which 
can be united and run into a middlings scalping reel for the purpose of 
separating the middlings from the flour. Say this is done on a No. 9 
cloth. In a 100-hundred barrel mill.this separation could be made and 
the middlings graded on one reel, clothing two-thirds of the head with 
a No. 9 cloth, and the remaining third with, say, No. 3 or 4. What goes 
through the No. 3 or 4 will be fine middlings, and what tails over it, 
coarse. The product of the No. 9 would go to two reels below to 
have the flour taken out. Say the flour cloths were Nos. 12 and 14, 
there would then be an intermediate product between No. 9 and these 


276 


GRADUAL REDUCTION MILLING. 

numbers to be cared for; they are called dust middlings. This is a 
fine grade of middlings which is not usually run to the purifiers. If this 
stock is rolled two or three times on smooth rolls and bolted the second 
or third time on a centrifugal reel, the tail of the last reduction can go to 
the red-dog. The middlings, after being purified, and the coarsest 
sized, say once, should be reduced twice, each reduction requiring 
about two reels. At the tail of each first reel of these two reduc¬ 
tions would be a scalper. If these reductions were by millstones, No. 
7 would be a good number for the first reduction scalping cloth and No. 9 
for the second; or, if roller reductions were used, two numbers coarser 
on each. In case of millstone reduction this tail could probably go to 
the red-dog; or from roller reductions to the second reduction by smooth 
rolls of the dust middlings, which go through the No. 9 cloth of the 
middlings scalping reel previously mentioned. The cut-off and last tail 
of the second middlings flouring reel would go to the first reduction by 
smooth iron rolls of the last dust middlings from the No. 9 cloth above 
mentioned. The sixth reduction and red-dog now remain to be taken 
care of. Then there would be the tailings rolls and one reel to follow 
them. The tail of this reel could go to the red dog. 

The sixth reduction stock, having been scalped over No. 30 wire, the 
flour can be taken out on a single reel clothed with Nos. 12 and 14 
cloth at the head and a short piece, say of No. 3 or 4, at the tail. The 
product of this latter cloth would go to the red-dog, and the tail to the 
fine feed or shorts. The tail of the sixth reduction scalper would be 
bran. The red-dog, we will say, is ground on a buhr, and the flour 
bolted out on a centrifugal reel. The tail of the reel goes to the fine 
feed or shorts above mentioned. 

To recapitulate, it will be remembered that there were six reductions, 
with six scalpers. The product of these reductions was originally di¬ 
vided into three divisions, viz.: 1st, the product of the first reduction; 
2d, that of the second, third, fourth and fifth; and 3d, the product of the 
sixth reduction. 

Each of these divisions was for distinct handling, and of each of 
these divisions there were sub-divisions. Those of the first were: 1st, 
the low grade flour; 2d, the red-dog stock; 3d, the middlings. 

The second division, or that of the four middle breaks, was sub-divided: 
1 st, into coarse middlings; 2d, into fine middlings; 3d, into flour; 4th, 
into finest or dust middlings. 



GRADUAL REDUCTION MILLING. 


277 


The third division, or the product of the sixth reduction, was divided 
into: 1st, bran; 2d, low grade flour; 3d, red-dog stock; 4th, fine feed or 
shorts. 

The coarse and fine middlings from the first and second general divis¬ 
ions are purified. In this process the divisions are as follows: 1st, puri¬ 
fied middlings; 2d, tailings; 3d, dust room stock; 4th, middlings to be 
sized. 

The product of the sizings rolls is divided into: 1st, flour; 2d, fine 
middlings to the middlings bin; 3d, coarse middlings to the purifiers; 
4th, tailings. 

The purified middlings would be concentrated, and their reduction by 
millstones would bring about another division : 1st, flour; 2d, middlings; 
3d, tailings. The reduction of the second middlings by millstones would 
divide the stock into: 1st, flour; 2d, dust middlings stock; 3d, red-dog. 
The only difference that this reduction by rolls would make, would be 
that this material which is mentioned as red-dog stock would probably 
be sent to the dust middlings second reduction. The dust middlings 
first reduction would divide into: 1st, flour; 2d, second dust middlings; 
3d, tailings. The second dust middlings would further divide into flour 
and red-dog. 

The tailings rolls reduction would imply four divisions: 1st, flour; 2d, 
dust middlings; 3d, red-dog; 4th, fine feed. 

The red-dog divisions would be : 1st, flour; 2d, fine feed or shorts. The 
general result of this would therefore be flour, bran and shorts; or, to 
speak more broadly, flour and feed. 

The classifications and divisions noted at some length include all the 
separations made by the reels and purifiers. The classification, as it is 
made on the grinding floor, as the material passes to the reduction ma¬ 
chinery, is as follows: 1st, the six reductions of the wheat; 2d, the re¬ 
duction of the purified middlings; 3d, the reduction of the second puri¬ 
fied middlings; 4th, the sizing of the coarse middlings; 5th, the reduc¬ 
tion of the first dust middlings; 6th, the reduction of the second dust 
middlings; 7th, the reduction of the tailings; 8th, the reduction of the 
red-dog. If this were a roller mill, and presumably a small one, thir¬ 
teen pairs of rolls would be required, or there would be thirteen divis¬ 
ions of stock on the grinding floor. In this instance the mill would not 
be large enough to require reduction machinery in duplicate. There 
were thirty-six divisions enumerated by the separating machinery up 


278 


GRADUAL REDUCTION MILLING. 


stairs, not counting the scalpings, which would make forty-two. Such a 
scheme would require thirteen reels and, say, four or five purifiers for 
the separating machinery. 

It will be noticed that no mention has been made of the distinct grades 
of Hour. It is one of the beauties of the present system of milling that 
any desired mixture of dour products may be made. The ordinary way 
would be to make three grades, taking the dour from the four middle 
breaks, together with the drst and second reduction of the dust middlings, 
for the clear dour; the dour from the drst and second sizings and drst 
and second middlings for patent. Then the dour from the drst break, 
sixth reduction and drst and second low grade stocks and bran duster 
dour would make low grade. Now there are changes which may be 
made in the low grade separations which would prove more prodtable 
than the one just mentioned. They include the making of two low 
grades, taking the sixth reduction and the dour from the reduction of 
the drst low grade stock for the drst low grade, and the dour from the 
drst reduction, second low grade reduction and the bran duster for the 
second low grade dour. On a mill operating on the basis of four bushels 
and thirty pounds of wheat, the drst low grade, if made out of winter 
wheat, will grade a XXX St. Louis standard, while the second low grade 
will be a super of the same standard. There will be about twice as 
much of the former as of the latter. If the two were mixed they could 

s 

not be much better than an extra. Now, as to which pays the best, is 
a simple question in arithmetic. If the writer mistake not, the XXX is 
an easier grade of dour to sell than any other. This is a question which 
every miller can decide for himself. 






THE HUNDRED BARREL MILL 




CHAPTER L. 


INTRODUCTION OF THE IOO-BARREL MILL PROPOSITION—THE LIMIT IN 
PURIFICATION—GRADUAL REDUCTION OF MIDDLINGS. 

In considering the processes and all the various details of milling, it is 
not remembered that any attempt has been noticed to show up the broad, 
underlying principles of hour manufacture as it is now carried on. These 
principles may be well understood and yet not expressed, or not ex¬ 
pressed well. In passing over this idea as hastily as must be done here, 
it cannot be hoped to do it the justice that would be wished. 

The purpose of the milling of wheat is to get it into such shape that 
it can be made into bread, the idea being to get the most money out of 
it, and the process of so doing is to make the most bread out of the 
Hour. Thus we have, as a purpose, the most money out of the wheat, 
and, as a means, the most hour out of the wheat and the most bread 
out of the hour. It so happens that the most bread can be made out 
of the purest hour, the purity of anything being always estimated with 
reference to its complete fitness for the purpose for which it is intended. 
A thing might be spoken of as pure for one purpose when it would not 
be pure for another. The best bread is that which is best to eat, and 
the best hour is that which will make the best bread and the most of it. 
The best milling is that which will make the best hour and the most of 
it out of a given quantity of wheat. Now, if pure hour makes the best 
bread, the means of making pure hour is the logical sequence in this 
consideration. It is a question of process and the machinery to bring 
about that process automatically and economically. As to the process, 
and as a part of the desired end, reduction is the first great step, and 
separation the second. Purification is the controlling idea as to the 
quality of the product. Reduction is a necessity in order to get the 
wheat into hour form, and the success of the operation is the value giv¬ 
ing element. Where the cleaning of the wheat has to do with the re¬ 
moval of the impurities which are a part of it, it belongs to the purifying 
process. If we could thoroughly purify wheat—if its impurities were 
all on the outside—we would never have had the middlings purifier in 





281 


GRADUAL REDUCTION MILLING. 

the first place, gradual reduction in the second, or bolting machinery 
either, only in so far as it was desirable to grade the material—a neces¬ 
sity brought about by incomplete reduction. If such a thing could have 
been done, this machinery would have been entirely unnecessary, ex¬ 
cepting as developed by imperfect reduction devices. The fact that 
there are particles of matter scattered throughout the grain of »vheat 
which are deleterious to the bread-making qualities of the Hour, was 
what developed the necessity for the middlings purifier as a purifier of 
broken wheat. 

It was for the purpose of purifying the wheat that the middlings puri¬ 
fier was invented, and it was for the purpose of making more stock 
which could be purified—that is, middlings—that the system of gradual 
reduction was arranged. In the sense that a middlings purifier is in¬ 
tended for broken wheat, it is desirable that a large proportion of the 
stock should be maintained in this form rather than in the finer particles 
known as Hour. The reason that middlings can be purified and Hour 
cannot, commercially, is clear when the principles of the purification of 
middlings are stated. The impurities in middlings are either larger in 
size, less in specific gravity, or different in structure from the desirable 
portion of the middlings. In event of the impurities being larger, they 
may be separated from the middlings by the bolting cloth. In event of 
their being of less specific gravity, air currents are arranged so that the 
lighter particles may be sent in one direction while the middlings take 
their natural course in another. The separation according to the differ¬ 
ence in structure is made by rolls. For instance, germ maybe fattened 
while the middlings will be broken, or apiece of bran may pass through 
smooth rolls intact, while the middlings, which were of the same size as 
that piece of bran, would be broken into several pieces. By such 
an operation, the question of separation becomes merely one which 
has reference to the size of the impurities. The germs of the wheat be¬ 
ing larger than the middlings with which they are mixed, is readily sep¬ 
arated by bolting cloth, as before stated. 

It is said that middlings are made in order to purify the wheat and 
for the reason that those impurities are not all external. It does not 
follow that the wheat can be purified by the mere reduction to middlings; 
and their treatment as such by the purifying agencies mentioned, but it 
does follow that the fracture of the wheat liberates certain of the con¬ 
tained impurities, and as there are impurities contained in the unreduced 


282 


GRADUAL REDUCTION Mil.LING. 


middlings themselves which would get into the Hour by an immediate 
reduction of the middlings after their handling by the purifiers, it follows 
that the gradual reduction of the middlings is as necessary as is the 
gradual reduction of the wheat. As this gradual reduction continues, so 
does the purification. Gradual reduction and purification go hand in 
hand. It is gradual reduction a?id purification. This is milling, and 
anything less complete is in the same degree incomplete milling. 

There comes a point in the gradual reduction of the wheat when we 
cannot longer take ^ofif middlings of such a size as to commercially 
purify them. It then remains to take oft' all of the Hour remaining on 
the bran. In the process of making middlings certain particles of the 
wheat and of the contained and other impurities, are broken into such 
fine pieces that they cannot be treated by the purifying agencies men¬ 
tioned. It remains to handle such material on reels, taking out such 
part as is known as flour, and making a separation of stock which may 
be designated as dust middlings, they being between middlings and flour. 
The purity of this stock may be very much enhanced by the action of 
the smooth rolls and the following reels as purifiers, in that they remove 
a portion of the impurities. 

The same thing happens in the gradual reduction of the middlings, 
though in that instance there is less effort to prevent the production of 
flour. But at the same time its production is gradual in order that the 
middlings may be of such a size as to admit of purification and other 
reductions. Milling is a process of reduction and purification, and in 
order that the purification may be more perfect, the reduction and puri¬ 
fication must be gradual. The reduction of the wheat has in mind the 
production of middlings for purification. The gradual reduction of 
middlings has in mind their gradual purification in order that it may be 
more complete. It is more complete by being more gradual, because 
there are contained impurities in the middlings which are liberated or 
detached with each reduction. 









CHAPTER LI. 


CONSIDERATION OF THE REDUCTIONS AND SEPARATIONS NECESSARY FOR 
. A IOO-BARREL MILL—MECHANICAL AND COMMERCIAL CONSIDERATIONS 
FOR MILLBUILDING—COST OF FLOUR—QUALITY OF FLOUR—CONDITIONS 
INFLUENCING THE COST OF FLOUR—COST OF OPERATING A MILL-IN¬ 
FLUENCE OF HARD AND SOFT WHEAT ON THE PLANT-FIRST REDUC¬ 

TION. 

What reductions and separations are necessary in a ioo barrel mill ? 
In answering a question of this kind it is well to consider in a general 
way what a mill of this size implies and what it does not imply. It 
does not mean simply the making of ioo barrels of flour in twenty-four 
hours, but, on the other hand, it does suggest the enumeration of the 
elements necessary to make ioo barrels of flour in that length of time, 
at a cost and of a quality which will admit of its being sold in the gen¬ 
eral markets at a fair margin under ordinary circumstances. An answer 
to this question which would be two years old, would not be an answer 
to-day. It requires a better mill to make money now than it did two 
years ago, and this state of the case would be true at this time, even 
though the unusual conditions influencing the market were not present. 
The mechanical and commercial considerations in miilbuilding must go 
hand in hand. A miller cannot run his mill on the reputation of a sin 
gle grade of flour, say patent. He has to make a good patent—a fair 
percentage of it—a high grade clear, and a small percentage of low grade 
which is well bolted. 

The merit of flour plays a more important part in its sale that it once 
did. Not but that merit is necessary, and always necessary. It will be 
remembered that certain high grades of flour once had a reputation 
which stood up like a stone wall. As long as the quality was uniform, 
it was not so much a question of price as it was of getting the flour. 
Outside flours of equal merit and less cost could not easily force their 
way into the lines. It was sold by the name on the barrel, and no one 
took the pains to examine it when making the purchase. It is not so 
now. 'Phe best established brands, in many instances, have to compete 




284 


GRADUAL REDUCTION MILLING. 

with other Hours of equal merit. Therefore it may be said that the mat¬ 
ter of quality, independent of reputation, is gradually playing a more 
important part in the sale of Hour than it formerly did. Not but 
that reputation is valuable and does make a difference in the sale of 
Hour, but it is undeniably true that it is easier to work in a truly merit¬ 
orious flour now than it was several years ago. There is one element 
of reputation which a miller may have and always profit by—an element 
which it is hard to disturb—and that is the reputation of furnishing a 
uniform grade of goods. A dealer may pick up a sample on ’change 
in New York and say: “Here is a Hour which is as good as Smith’s, ” 
but he cannot say that the next lot or shipment will be as good as 
Smith’s, and for that reason if he buys the former it would be at a dif¬ 
ference in price which would probably leave Mr. S. a milling margin. 

It is not so much a question of choice how much of a mill a man 
builds now, how complete it is in system, as to the number and quality 
of the reductions, as it was formerly. A miller who intends to compete 
with or do business in the general markets, cannot say: “I will build a 
three or four break mill and other things in proportion, and content 
myself with a smaller margin than if I chose to invest more money. ” 
Where he has only three or four break mills and buhr mills to compete 
with, mills which do work of that quality and cost, that maybe all right, 
but demand and supply suggest something different. The demand is 
for the best thing, and the supply is by more elaborate means than those 
of a three or four break mill, hence a competition on a more elaborate 
basis. According to this it is not a matter of choice as to how com¬ 
plete the milling system may be, but a question of demand. It is a 
question which is settled by the goods on the market and the means of 
making those goods. 

The next question is as to what is the demand of the market as to the 
quality of the goods, and their cost as well. The quality of Hour is a 
difficult thing to describe on paper. One might write forever and not 
be able to convey to a man born blind what is meant by a color, and 
especially the names of the colors. There is no definition which will 
convey to one’s mind the idea of redness. At the same time there is 
no means of describing in print the quality of Hour. One may speak 
of a patent and a general impression is conveyed, but as to the quality 
of the patent he is left in the dark. One cannot estimate quality by 
the prices, because that is a variable quality. Comparative merit, in the 



GRADUAL REDUCTION' MIIJTNG. 


285 


absence of fixed and recognized grades of differences, is the only basis 
for consideration. We can only say that we have to meet the market 
as to quality, that we want to make flour as good as the best, taking 
into consideration the quality of wheat used. Hence, knowledge of 
what is the best and knowledge of the demands of the market is a 
necessity to him who proposes to erect a mill to meet the demands of 
that market. 

The cost of flour maybe influenced, (1) by the cost of the operation 
of the mill; (2) by the amount of stock used; (3) by the proportion of 
the various grades made; (4) by the value of the various grades. Three of 
these conditions may be favorable, and a fourth being neglected, the 
profits of the mill may be seriously impaired. For instance, the ex¬ 
pense of running a mill might be exceedingly low, the quality and yield 
all right, and the amount of stock used down to a reasonable basis, and 
yet, because of a neglect of the percentages, the profits of the mill 
might be destroyed. It should be remembered that the question of 
yield is to be estimated not alone by the amount of stock used, but as 
well by the percentage of various grades of flour derived therefrom. 
There is still a better way of estimating than this, and that is the pro¬ 
portional increase in the price of the wheat, as influenced by its milling. 
That is, the mill which will take a bushel of wheat and add the most 
value to it is the best mill. This is the quality in mills which it is diffi¬ 
cult to estimate, but it is clearly to be seen that the question of the 
product is inseparable from that of yield, when properly considered. 

The cost of operating a mill is influenced by mechanical considera¬ 
tions—the quality of the machinery and the convenience of its arrange¬ 
ments. A consideration of these elements would develop a more lengthy 
description than it is well to make here. The amount of stock used, 
the proportion of the various grades and their values, is to be met by 
the quality of the machinery as adapted to its uses, the arrangement as 
forming the milling system, and the skill with which it is operated. 

All this has direct application to a j 00-barrel mill, as it has to one 
that is larger or smaller, and in any mill there is the embarrassing feature 
of hard and soft wheats to be considered. One could very easily work 
out a plausible theory to show that the amount of grinding surface could 
not be influenced as to its capacity by the hardness or softness of the 
the wheat on any one of the reductions. The basis upon which this 
idea would be worked out would be that the proper grinding capacity of 


2 86 


GRADUAL REDUCTION Mil.LING. 


a pair of rolls is a fixed quantity, fixed by the amount of material which 
will pass through the rolls, each granule of which will be evenly touched 
on both sides. Any more than this would result in the various particles 
being mashed together and not reduced by the rolls themselves in the 
strict sense of the idea. The same fine spun theory would point out 
that a less amount than the proper fixed quantity of stock would involve 
the waste of good milling machinery. This idea that the grinding ca¬ 
pacity of a pair of rolls is fixed on various qualities of stock, would be 
drawing entirely too fine a bead on the whole business. The fact is that 
a mill can make more flour in the same number of hours, with the same 
amount of machinery, out of hard than it can out of soft wheat, and not 
alone on account of the fact that the hard wheat bolts more readily than 
soft, but because it is more readily reduced. Soft wheat assumes greater 
bulk in the process of reduction than does hard. By this is meant that, 
say on the third or fourth reductions of the wheat, there will be a larger 
amount of stock to be reduced in the case of soft wheat than of hard. 
But at the same time the difficulty of reducing soft wheat is greater than 
that of hard. It is more tenacious—holds together longer; it occupies 
more space and is more bulky. In the wheat reductions the bran is 
larger. When it comes to reduction of middlings by smooth rolls, the 
work has to be done more slowly with soft than with hard wheat. Take 
the case of the very large middlings—the middlings which are to be 
sized. It takes a greater number of reductions to bring the middlings 
down to the proper size, and at the same time preserve their quality 
with soft than with hard wheat. Furthermore, this same principle applies 
equally all the way through the mill—to the dust middlings and red-dog 
stocks alike. 

It takes more mill to make ioo barrels of flour out of soft wheat than it 
does out of hard—the time being the same, of course. A mill which would 
make ioo barrels of flour in the twenty-four hours out of four bushels 
and thirty pounds of soft wheat, will make more than that amount of 
flour out of hard wheat with the same yields. This thing sometimes occurs 
in mills which run to a uniform capacity, which regulate their grinding 
by the packer registers—mills which make ioo barrels of flour in twenty- 
four hours, regardless of hard or soft wheat. With regular grinding this 
will sometimes occur. They may be grinding soft wheat and making 
6 or 8 per cent, of low grade, but, on changing to hard wheat, they 
may make from io to 12 per cent, of low grade. With this result the 







GRADUAL REDUCTION MILLING. 


287 


conclusion might be reached that the “hard wheat made too much low 
grade.” Not so, however. It is simply meant that the yield was bet¬ 
ter, and that the miller was getting more Hour out of the tail end of the 
mill—that he is getting more Hour into the low grade packers and less 
into the feed pile. If he had increased the production of Hour when 
changing from soft to hard wheat, the amount of low grade might have 
been the same and the yield the same. 

In hard wheat milling the size of the middlings is more nearly uniform 
and consequently fewer operations are required in their reduction and 
purification. The number of classifications for the latter purpose need 
not be so great. The matter of sizing and purification between sizings 
is much more important in the case of winter wheat milling than with 
spring wheat. Not but that sizing is necessary in both, but more sizing 
and more intermediate purifications are necessary in the former case than 
in the latter. All this that is said about grinding capacity goes to show 

how uncertain and how unreliable a direct and dogmatic answer to the 

♦ 

question as to how much machinery is necessary for a 100-barrel mill, 
would be. The safe thing to do on winter wheat w.ll be to take Fultz 
wheat of the ordinary degree of softness as a basis. Then if the wheat 
be harder, the capacity of the mill will be greater. 

Take the first reduction: One pair of 9x18 rolls is about right. 

Less would do for this reduction, from the fact that a first reduction 

never fulfills its promises. It does not split the wheat with any degree 

■ 

of uniformity, and it does not release the “crease dirt” to any great ex¬ 
tent. Eight corrugations to the inch is the usual thing at this stage of 
the proceeding, though various other arrangements and combinations are 
frequently mentioned and vouched for—such as a coarsely corrugated 
roll run against a smooth roll, the running of the dull backs of sharp 
cut rolls against each other, and the running of them at various differ¬ 
ential motions, and at integral motion ; that is, both rolls at the same 
speed. From 200 to 225 revolutions per minute is the proper speed. 
The scalping reel should be clothed with No. 20 wire, though coarser 
middlings than this would be made on an eight corrugated roll. As far 

1 

as the separation goes, this scalper need not be more than two feet long, 
but as a longer reel does good service in other respects, it is well to have 
it of greater length, say four or five feet. The Hour reel from this break 
need not be over twelve feet long, the first two-thirds of it being clothed 
with No. 14 cloth. The coarse middlings which go into this reel will 


288 


GRADUAL REDUCTION MILLING. 

make it bolt abundantly free, so that lack of capacity need not be feared. 
No. 8 cloth at the tail, the product of which can be sent to the low 
grade rolls, will dust the coarse middlings sufficiently and free them from 
the lighter impurities to such an extent that they may be sent to the 
grader, or to the scalpers, if the grading be done in that way. 





CHAPTER Ell. 

THE RELATIVE AMOUNT OF MACHINERY FOR A IOO-BARREL MILL-MA¬ 

CHINERY FOR SMALL MILLS—CONSIDERATION OF THE FOUR MIDDLE 
BREAKS-PRODUCT OF THE FOUR MIDDLE BREAKS. 

The same principles apply to the construction of ioo-barrel mills, or 
other small mills, as to larger ones, although, in the latter, finer points of 
reduction and separation can be recognized. In the last year or so we 
have heard a great deal about machinery for small mills—reduction and 
separating devices—being various arrangements which propose to do the 
same work at a less cost of plant than if done by the regular milling ma¬ 
chinery in general use. For these same small mills has been arranged 
reduction machinery, the claim for which in some instances is to do in a 
single operation what is done in other instances in larger mills by two or 
three reductions, and, at the same time that this short cut as to the ex¬ 
pense of milling the wheat is claimed, no allowances are made for an 
inferior quality of work. Now, all this is preposterous; not but that it 
is desirable to make special and less expensive machinery for small mills, 
but on account of the claims of the quality of their work as compared 
with the more complete and logical methods. 

It will be remembered that soon after the gradual reduction process 
was first announced, various competing millstone dresses were brought 
out, the inventors of which, in some instances, announced that they had 
accomplished the whole business between the eye and the skirt of the 
millstone. These claims have gradually been softenirg down, and as 
time passes they approach a more reasonable basis. Still they have not 
yet fully reached the point where it is recognized that the machinery 
which is best adapted for a large mill is the only proper machinery for 
small ones which desire to do the same quality of work. In point of 
fact it is merely a question of reduction and separating capacity. To be 
strictly logical or reasonable, it may be well to say that the length of the 
rolls and the number and length of the reels and the size of other re¬ 
duction and separating machines marks the difference in capacity. 

(*9) 


290 


GRADUAL REDUCTION MILLING. 


The question of quality of machinery cannot indicate the capacity of 
the mill. The fact that a mill is making 100 barrels of Hour in twenty- 
four hours does not suggest the idea that its machinery is in any way 
inferior to one which is making 500 in the same length of time. 

This fact is being recognized 
by some of the large millbuilding 
concerns, who are making ma¬ 
chinery of the same general de¬ 
signs and of the same quality, but 
smaller in size and capacity than 
that used in the larger mills. An¬ 
other idea on this same line is a 
point in regard to the often asked 
question as to whether small mills 
can be made to do as good work 
as the large ones—can compete 
with the latter. They can, but 
as a matter of fact they do not. 
They can do as good work 
if arranged on the same basis 
and operated with the same 
skill as the large ones, but, as a 
rule, a single pair of 9x18 rolls 
will have from a half more to 
twice as much work to do in a 
small mill as a large one. The 
same is true as to the reels and 
purifiers. The reduction and sep¬ 
arating devices are more often 
overworked in small than in large 
mills, and for that reason the lat¬ 
ter more universally do work su¬ 
perior to that of the former. 

In the last chapter the first 
break was considered and the 
course of the stock fully illus¬ 
trated. A diagram of this break 
and the separations as previously 



















































GRADUAL REDUCTION MILLING. 


291 


described, together with the breaks and separations of the second, third 
and fourth reductions, is herewith submitted. The second break is made 
on one pair of 9x18 rolls with ten corrugations to the inch. Twelve 
are sometimes used, and occasionally even finer, but the writer prefers 
the former, as it leaves the stock in broader shape—not so much cut up 
—for the third break. No. 20 wire is used on the scalper, which is six 
feet long. Were hard wheat used on this mill, a shorter scalper would do. 

The third break is made on one pair of 9x24 rolls, with fourteen cor¬ 
rugations to the inch. This corrugation, as understood, suggests No. 22 
wire. As said before, the size of the middlings is largely influenced by 
the size of the corrugation, the quality of the stock being such as is de¬ 
manded by the reduction of this corrugation. The third break scalping 
reel in this mill would be about seven feet long. 

The fourth break reduction is made by thirty inches of reduction sur¬ 
face, corrugations sixteen or eighteen, preferably the former, with 
the reel eight feet long, it being well understood that, as the reduc 
tions advance, the length of the reel should increase. 'The quality of 
this stock and number of the corrugation invites the use of No. 24 wire. 
It is well known that all of the middlings made on each reduction should 
be taken out on the scalper for that reduction, and that if the scalping 
wire be not accommodated to the number of the corrugation, or the size 
of the middlings made, the idea and purpose of gradual reduction methods 
will not be fully realized, in that middlings may be carried over from one 
break to another, or, in case of the wire being too coarse, larger stock 
than is desirable will be carried in with the middlings, which would, in 
order to get rid of the stock properly, invite the use of a larger plant o^ 
smooth rolls, scalpers and purifiers than is usual or desirable. 

The product of the second, third and fourth breaks is run together, 
the fifth break chop being cared for by itself, as will be described later. 
The middlings from the three breaks named are scalped over Nos. 8 and 
9 cloth—this and the two following reels being fourteen feet long. The 
tail of this scalper goes to the grader, It will be noticed that the upper 
conveyor is arranged so that any part of the tail of the middlings scalper 
may be sent direct to the dust middlings. If this stock should have the 
Hour all taken out of it—should be sharp and ragged—there is no need 
of sending it to the flour reels. The same arrangement may be noticed 
at the tail of the next reel. In either case, if desirable, the entire prod¬ 
uct of that reel can be sent to the one next lower by merely closing 



2C)2 


GRADUAL REDUCTION MILLING. 


slides. The flour numbers on the second reel are Nos. 12 and 13, and 
the tail or scalping number is 8. The second flour reel is clothed with 
Nos. 13 and 14. The cut-off from the bottom conveyor can be sent 
either to the dust middlings rolls or the dust middlings elevator. In one 
instance it would be reduced; in the other it would not, this depend¬ 
ing upon the quality of the flour. It is understood that the tail of this 
reel will always go to the dust middlings rolls. 



CHAPTER MIL 


THE FIFTH BREAK—ARRANGEMENTS FOR CARING FOR THE PRODUCT OF 

THE FIFTH BREAK. 

Next in order comes the fifth break. It is on this break that the results 
of good grinding can be clearly realized. The product of the third and 
fourth breaks is pretty sure to be reasonably good under any circum¬ 
stances, but any differences on these breaks will operate to the disad¬ 
vantage of the fifth. The point in good grinding is always to keep the 
stock as broad as possible—to maintain the bran in large Hakes. What 
we want to do is to reduce the Hour stock and come as near as possible 
to letting the impurities alone. If we could get the bran from each 
kernel in one piece, we would be reasonably certain of getting little or 
none of it in the Hour. The same thing applies to other impurities, but 
as this is impossible, we do the best we can. We say that we will keep 
the bran broad, and, in other respects, disturb the deleterious stock as 
little as possible. Hence, the best grinding is that which comes nearest 
this point. 

It is particularly desirable that the stock go to the fifth and sixth 
breaks in this broad condition, and for that reason we must look to the 
other breaks—to the part of the mill ahead of these—to bring about 
this desirable result. The same grinding which will do this will reach 
the best results in other respects in the first four breaks. 

With soft wheat we can grind a little closer on the first two breaks, 
and still not disturb the bran for the latter breaks, than we can with hard 
wheat. With this kind of grinding on the wheat mentioned, it is possible 
to grind more open on the third and fourth breaks than would otherwise 
be allowable in order to get the proper final finish. By the means here 
suggested, the middlings on the third and fourth breaks from the soft 
wheat will be large, more readily dusted in that there will be less dust 
made, and brighter and freer from bran and bran specks. They will 
also be less inclined to be mushy or soft, and at the same time the 
quantity will be greater. In the case of hard wheat the grinding can 
be more uniform throughout, but should be less close on the first and 


294 


GRADUAL REDUCTION MILLING. 

second breaks, and with the idea of “grinding for middlings” on the 
third and fourth breaks, the desired results as to the delivery of stock to 
finishing breaks will be realized. 

In a ioo-barrel mill the fifth reduction should have thirty inches grind¬ 
ing surface to do the best work. It was a custom a few years ago, and 
one that is not altogether wiped out, to contract the amount of grinding 
surface after the fourth break. If anything should be done, it should 
be increased, the stock being bulkier and requiring more surface to 
properly operate upon than upon the previous break. This break re¬ 
quires more delicate handling, finer distinctions as to the adjustments’ 
and altogether more intelligent handling, when considered by itself, than 
do any of the other breaks. 'Twenty corrugations to the inch are un¬ 
questionably the best for this reduction, and No. 26 wire, or the corre¬ 
sponding size of grits gauze is used for the scalpers. Eight feet is the 
proper length for the latter. 

A mistake is made in running the product of the fifth break in with 
that of the other middle breaks; that is, the second, third and fourth. 
As a general thing, it will be found that the quality of the flour from the 
fifth break is superior to that from the second, but that the middlings are 
very much inferior, and with soft wheat not only is the quality inferior, 
but the quantity is small. The amount of middlings from th : s break is 
even less than is usually supposed. There are some very fair middlings 
which will pass through a No. 4 cloth, but even these are not of the 
right quality to go in with the middlings from the other breaks. This is 
more particularly true of soft wheat stock. The material which will tail 
over a No. 4 cloth is little better than tailings. 

On a plant of the size of the one in question, the diagram in Fig. 1 in¬ 
dicates the solution. The tail of the No. 4 cloth goes to the tailings; 

the product of that cloth, consid¬ 
ering the size of the plant, goes 
to the dust middlings; a portion 
y, ( i', 1 t ^ e flour fr° m the upper con¬ 

veyor goes to the bakers’; and 
the cut-off to the dust middlings 
F *s- *■ flour reel. This can be done by 

spouting it directly into the elevator which takes the stock from the 
dust middlings rolls. 

'The diagram in Fig. 2 indicates another means of handling the same 

















GRADUAL REDUCTION MILLING. 


2 95 


stock. It will make better dour and better separations generally. The 

coarse stock is sent to the tailings as before, and the product of the 

No. 4 cloth to the fifth break middlings purifier or purifiers. The stock 

which goes through the No. 8 cloth on the upper reel has enough of 

coarse material taken out of it so 

that it will bolt clean and bright 

on the reel below. There is one 

point to which the writer clings 

4—- 1 » -->—very strongly, and that is to re- 

-r-- ""her. ducing the proportion of sharp 

12 13 u 6 7Vr 

-- iW,??. or 2rf material to the utmost degree con- 

Ofn ,0n fo 

sistent with the possibility of bolt¬ 
ing it before taking out dour. The 
Fig. 2 . progress of the stock is suffi¬ 

ciently indicated on the Matter diagram so that further explanations are 




not necessar 

















CHAPTER LIV. 


THE SIXTH REDUCTION—CAPACITY REQUIRED FOR TH? SIXTH REDUCTION 
—OVERLOADED BRAN ROLLS—SCALPERS FOR SIXTH REDUCTION-DIA¬ 
GRAM FOR BOLTING SIXTH REDUCTION STOCK-SIXTH REDUCTION 

FLOUR. 

The sixth reduction of the wheat being the last, it is well that it have 
due consideration. It is the last reduction of the wheat proper, and at 
the same time it is the first reduction in the process of milling where we 
begin to throw stock into the feed pile. It is spoken of as being first, 
perhaps not in its milling sense, but first in general classifications. In 
considering a mill in this way, it is natural to take the breaks first, and 
then the products of these breaks, considering in due order such as are 
of first importance in the division—the middlings. Then there would 
come the finer stock as to size, not quality, and next the coarser, or red- 
dog stock. If we were to consider that which went into the feed pile 
first in point of time in the process of the milling of the wheat, it would 
probab’y be a portion of the reduced red-dog stock from the first reduc¬ 
tion, this material making the shortest cut from the wheat to the feed 
pile. This statement is a mere novelty, and has no special significance 
or value from a milling standpoint. It is like answering a question 
which one frequently hears from mill visitors as to how long it takes the 
wheat to get through the mill. 

But to return to the sixth reduction: Only a few years ago, in most 
of the diagrams then made, the capacity of these rolls was much less 
than that of the middle reductions and usually about the same as the 
first. The character of the stock which goes on these rolls invites 
a different condition of things. It is bulkier, occupies more space, 
requires a larger elevator to carry it than the others, and requires 
more reduction surface to handle it than any other breaks in the 
mill. But one has to preserve a little policy in these matters, and the 
most that can be suggested is that the sixth reduction should have 
fully as much grinding capacity as any other in the mill. The 
sixth being the last of its class, and being one which sends a larger 


GRADUAL REDUCTION MILLING. 


297 


quantity of material to the feed pile than does any other, it is important 
that this work should be done thoroughly and well. Where the capac¬ 
ity is limited, the quality of the finish at this point must necessarily be 
materially influenced, and in a way to have a very decided bearing on 
the cost of the flour. The amount of grinding surface which will do the 
Ibest work at this point in the mill is that which will come nearest to 
scraping each particle of bran. This word scraping is used not because 
it is entirely satisfactory in this sense, but as being the one which most 
nearly conveys to the mind the idea of the proper mechanical process 
in the reduction of the stock under consideration. The words breaking 
or grinding lose their true significance in this part of the process, having 
presumably a proper significance only when applied to the making of 
middlings. The process which will most thoroughly scrape the flour 
from the bran without fracturing the latter, is the one which most thor¬ 
oughly realizes the idea of its cleaning or finishing. 

Where the bran rolls are overloaded, only a certain proportion of this 
stock is submitted to the action as above described. The material which 
is in excess of the natural or proper capacity of the rolls is influenced 
•only by compression, by the friction of one particle against another, in¬ 
stead of by the scalping influence of the rolls themselves. The same 
ideas which were mentioned with reference to the condition of the stock 
as it passed to the fifth reduction, as applying to its desirable broadness 
and freedom from flour and fine stock, applies with equal force to the 
sixth reduction. The writer has seen stock from the tail of the tailings 
roll reel run to this reduction, and also material from the tail of the siz¬ 
ing reel. Whatever benefit there might be gained from the material in 
•question, it is largely overbalanced by its bad influence upon the proper 
stock for these rolls. In the first place, it will not feed so regularly or 
evenly, and in the second place it greatly interferes with the reduction 
of the bran. 

In this ioo barrel mill thirty inches of grinding surface is necessary 
for the desired results, twenty-four corrugations to the inch is dictated 
by general experience, and No. 30 wire is commonly used. The best 
-scalper for the sixth reduction is a common form of centrifugal reel. The 
•device which is in mind can hardly be called a reel, in that the outer 
■cylinder does not revolve, but has the spiral beaters on the inside to agi¬ 
tate and propel the stock. It is not known that such a machine is reg¬ 
ularly on the market, though it was several years ago, being sold and 


298 


(GRADUAL REDUCTION MILLING. 


C5 


improperly used for scalping wheat chop from millstones. Considering 
their cheapness and the quality of the work done as a sixth reduction 
scalper, it is strange that they have not been made and sold for this pur¬ 
pose. A scalper six feet long, of the kind mentioned, will take the stock 
from a 500-barrel mill and make a very superior separation on this class 
of stock; that is, there will not be a suggestion of detached hour or mid¬ 
dlings on the bran as it leaves the tail of the machine. Scalpers three, 
four and five feet long might be made; the first size would be ample for 
a 100-barrel mill. They are a terror to the miller in the matter of keep¬ 
ing the cloth whole, until he strikes the idea of putting on a coarse cloth 
of about a quarter inch mesh and finer inside of that, the cloth being 
put on from the inside of the reel and divided in half longitudinally. 
The coarser cloth is secured with double pointed tacks, or small staples. 

The diagram given here shows the reduction and separation of the sixth 
break stock, the tail of the scalper going to the bran duster, and the tail 

of the reel to a secondary scalper 
which makes three separations, viz.: 
the flour stock, the red dog stock and 
the fine feed or shorts. The quality 
of the former can be regulated by 
the quantity of stock sent to the red- 
dog. This separation of the Hour 
stock from the coarser material 
should be made on as fine a cloth as 
possible, or one which would make 
the separation itself without running 
'£e e rich material to the red-dog, keeping 
in mind only the possibility of bolt- 
^ ing this material on the centrifugal 
reel below. This is done with the 
idea of reducing the proportion of 
coarse material in this flour stock to 
as great an extent as possible, thus 
getting a better quality of flour from 
the centrifugal reel bolting ibis stock 
than would otherwise be possible. 
The flour from this reel would be white and bright looking under the 
spatula, though its doughing qualifies are not sufficiently good to admit 


24 Corrugations. 

30in Grinding 
Surface. 



No 9 or 10 

2 

//// 


-^ 


Centrifugal Reel 6’ long. 








13 14. 



< 


-W- 
































GRADUAL REDUCTION MILLING. 299 

of its going in with the high grade. It is dark in the dough, but is the 
strongest hour in the mill. Its color when wet is the only thing against 
it. At the same time that it cannot go with the high grade Hour, except 
in occasional instances, it is very much superior to the red-dog Hour, 
and in a small mill it is a problem what to do with it, but in any event 
it will pay to pack it by itself. This will not require any additional 
packer, but by submitting to the inconvenience of running it into sacks 
and packing it once or twice a week on the low grade packer, it will be 
found that the inconvenience is more than overbalanced by the return 
to the miller. 


CHAPTER LV. 


[PURIFICATION FOR A IOO-BARREL MILL—GRADING OF THE STOCK-GRAD¬ 
UAL REDUCTION OF THE MIDDLINGS-USE OF ASPIRATORS IN A IOO- 

BARREL MILL-USE OF SIZING ROLLS—THE ANALOGY OF THIS METHOD 

TO HUNGARIAN METHODS. 

The cut here given represents the diagram which gives the purifica¬ 
tion system for the ioo-barrel mill. It will be noticed that there are five 
grades on the grader and three grades for purification—two of the divis¬ 
ions made by the grader being run together before they pass into the 
aspirating purifiers. The first grade, which goes through a No. 3 cloth, 
passes on an ordinary sieve purifier. The middlings which pass through 
the Nos. o, 00 and 000 cloths, after having passed through the aspirating 
purifier in two divisions, are sized on smooth rolls. The Nos. 00 and 
■000 grades are sized down to the No. o grade and the No. o middlings 
to No. 2. These numbers—the No. o and the No. 2—may be noticed 
under the sizing rolls for the grades named. 

The stock which passes over the tail of the No. o in the first sizing 
and the No. 2 in the second goes to the tailings. The stock which 
passes through the No. o of the first scalper goes to the second sizing 
rolls, and the slock which passes through the No. 2 cloth goes to the 
sizing purifiers below. The fine middlings and flour which pass through 
the No. 6 cloth go to the flour reel below. The material which passes 
through the No. 5 cloth on that reel goes to the middlings bin. It is 
arranged so that any portion of the product of that No. 5 cloth may be 
sent to the tailings. It would very seldom be regarded as necessary to 
send more than one slide of that stock in that direction. 

It will be remembered that the writer has referred to smooth rolls as 
purifiers. They are used especially for that purpose in this diagram. It 
is hardly necessary to go farther into the description of this diagram. It 
may be well to note, however, that the aspirating purifiers have four 
legs, each of which is connected with a suction fan in the middle. A 
•detailed drawing of two of the legs of this purifier is shown in the cut. 



Tailings. 


Patent Flour. 












































































































































































































































GRADUAL REDUCTION MILLING. 


3°S 


The cross section shows a gravity separator or aspirator, which may 
need a little explanation. It is a form of purifier which is largely used 
in Hungarian milling. Not this particular one, but of the same kind 
and general principles. The purifier here illustrated is a suction ma¬ 
chine. The direction of the suction is between the slats £ and £, and 
toward the opening B, the size of which opening and the force of the 
suction being regulated by the valve E. The middlings pass between 
the slats E and F in a downward direction, and are defiected from side 
to side, their progress being arrested by these. The suction draws the 
particles of less specific gravity than good middlings through the open¬ 
ings /, and over the slat E into the chamber at the back thereof. The 
air, after it passes through the narrow openings, expands to a certain ex¬ 
tent and allows the larger portion of the impurities to settle and dis¬ 
charge through the opening G , which has a slat covering it in a manner 
similar to that of the discharge of a separator shoe. The pure middlings 
discharge through the spout H For this kind ot a purifier it is import¬ 
ant that the middlings passing down each leg or compartment should be 
graded very close. There should not be the difference of more than 
one number from one compartment to the next, or from one size to the 
next. By this means the suction can be adjusted according to the spe¬ 
cific gravity of the middlings and thus make a nicer distinction between 
the specific gravity of the good middlings and the impurities. With such 
a machine there is the grading sieve above, represented in the cut 
by A B , which is arranged to grade the middlings into the differ¬ 
ent grades. Under the grader there is a single leg of one of these aspi¬ 
rators, which is connected with the suction fan as shown in the cut. The 
sieve above the grader stands on hickory springs and has been described. 
The motion of the sieve should be from 325 to 350 per minute, and the 
throw about one inch. 

Those who have read this work carefully will remember that the writer 
includes the system of sizing in the purification arrangements, believing, 
as he does, that present knowledge on that subject demands the use of 
smooth rolls and the following scalping reels as purifiers. To make this 
belief more emphatic and clear, he will say that if he had to make a 
choice for the purpose of purification between smooth rolls and the ordi¬ 
nary sieve purifiers, he would choose the former rather than the latter. 

By reference to the diagram mentioned, it will be seen that the mid¬ 
dlings from No. 1 to No. 000 inclusive, are reduced so that they will all 


GRADUAL REDUCTION Mil.UNO. 


3 °4 

pass through a No. 2 cloth. It would be better to give these middlings 
still another reduction, so that all would pass through a No. 4 cloth, but 
this would invite a larger outlay than is usually thought desirable in a 
mill of this size. It is not possible to reduce winter wheat middlings 
any faster than the diagram indicates, and at the same time preserve them 
in that form which makes it possible to repurify the coarser product be¬ 
fore it is finally reduced to flour. If they are reduced more rapidly, the 
product will be flat rather than round, or, more properly speaking, rec¬ 
tangular. If the middlings are flat, rich stock may tail over the ma¬ 
chines, and the pressure used in making them flat will force the impuri¬ 
ties into the middlings stock, rather than separate it therefrom. With 
extremely hard wheat it might be possible to do this work faster, but the 
difference would be such as to admit of a less number of reductions 
than those here given. Hard wheat middlings break into a larger num¬ 
ber of pieces under the influence of the sizing rolls. This not only im¬ 
plies a more rapid reduction, but as well a larger proportion of fine mid¬ 
dlings and a smaller proportion to repurify after the scalping. These 
facts might make it possible to clothe a little finer on the tail of the 
scalpers than was given in the diagram. 

The sizing rolls are set according to the stock which tails over the 
tail number of the scalping reels. For this reason it would be well to 
send the tail spout from these reels down to the first floor on their way 
to the tailings elevator, in order that examination thereof may be readily 
made in connection with the setting of the rolls. If the rolls be too 
open the stock will be rich, and if they be set too close it will be too 
rich—in the first place because the stock will be too large, and in the 
second place because it will be too flat. If this stock be flat, it will be 
next to impossible to get the flour out of it on the tailings rolls, and the 
same poor sizing which will make this class of tailings will also make the 
larger class of middlings so soft and flat that they cannot be purified. 
Middlings which have been treated in this way once have passed the 
point beyond which the purifiers can fully benefit them. Furthermore, 
the following rolls or reduction machinery cannot do their work as well 
on this class of stock in any respect as if it had been properly treated. 
The quality of the flour will not be as good, either as to color or granu¬ 
lation—which implies quality—or as to the amount thereof, which sug¬ 
gests the question of yield. After stock has been flattened once by the 
rolls, it has a tenacious, feathery quality which renders its farther reduc- 






GRADUAL REDUCTION MILLING. 


305 


tion slow, expensive, and finally incomplete. This merely goes to show 
that poor work on one reduction carries itself through the mill, affecting 
the quality of every following reduction and separation. 

The system of purification in American mills is not nearly so com¬ 
plete as in the Hungarian mills. This is the one place where our mill¬ 
ing is decidedly inferior to theirs. As understood, our arrangements for 
bolting the break chop in reduced middlings are superior to their method, 
but in the essential feature of the gradual reduction system, the purifica¬ 
tion and gradual reduction o r middlings, our arrangements are very much 
inferior to the Hungarian methods. Our neglect is in the purifica¬ 
tion of middlings during the process of sizing. It is true that the auto¬ 
matic way of handling stock in American mills is so different from the 
Hungarian method of handling by hand that the same classification 
is impossible. While the adoption of the details of the Hungarian 
method is hardly possible, the principles are readily adaptable, and in 
neglecting those principles we are neglecting the best part of Hungarian 
methods. The part of that system which we have adopted is the mak¬ 
ing of middlings, but the better part of their purification and sizings we 
have neglected. This system includes the gradual reduction and gradual 
purification of the middlings. It is the combination of the purification 
by the ordinary methods—that is, by the purifiers—and the sizings, in 
one system. 

While speaking of the neglect of possibilities in the benefits to be de¬ 
rived from milling on the Hungarian plan, it might be well to call to 
mind the cleaning of the wheat. So far as the writer is able to learn, 
their methods are very much superior to our own in this respect, and 
their arrangements of machinery for doing this work quite different from 
ours, though some of our machinery is used in their mills. There are 
very few mills where the wheat is well cleaned and scoured, and, as a 
matter of fact, very few changes or improvements have been made in 
this part of the mill since the days of low millstone milling. 

To recur again to the diagram of the purification system of the 100- 
barrel mill: The system there suggested is a mere approach to the ideas 
just expressed in regard to Hungarian purification methods. It carries 
that idea about as far as can be expected in a mill of the size of the 
one under consideration. It might be asked, why not send the mid¬ 
dlings from the sizings rolls—that is, those which go through the tail 
cloths, or the tails of the reels which follow the rolls—to the first sieve 


306 gradual reduction milling. 

machines, under the head of the grader, rather than to separate ma¬ 
chines as shown? It may be well to call to mind in answer to this, that 
middlings which have once passed through the sizing rolls are of a dif¬ 
ferent character from those which come from the break rolls, and for that 
reason demand a different handling. 




CHAPTER LVI. 


REDUCTION AND SEPARATION OF MIDDLINGS FOR THE IOO-BARREL MILL- 

SEPARATION FOR A REDUCTION 13V ROLLS—SEPARATION FOR MIDDLINGS 

GROUND ON BUHRS—THE SECOND MIDDLINGS-THEIR REDUCTION BY 

ROLLS. 

Herewith is given the arrangement for the reduction and separation 
of the purified middlings, 'ihe clothing of the reels, and more partic¬ 
ularly the fixing of the scalping numbers, should be considered in con¬ 
nection with the grinding, It is well to know how rapidly one intends 
to reduce the middlings, and then, by considering the size of the mid¬ 
dlings to be reduced, it will be determined what the scalping numbers 
shall be. These are more important than the Hour numbers, as by the 
scalpers the quality of the Hour from any flour number may be in¬ 
fluenced. It may have been noticed that the system of bolting followed 
out in this work has involved the gradual separation of the coarse from 
the fine material; that the idea has always been to keep the stock as 
soft as possible while in the reels, consistent with its bolting with or¬ 
dinary facility, without the use of wipers, knockers or other makeshifts. 
Such a system always brings the whitest flour possible out of the stock. 
By reference to the diagram in Chapter TV., it will be seen that the 
middlings are dusted over a No. 8 cloth, and range from that to such as 
will pass through a No. 2 cloth, those coarser than the latter number 
having been reduced to that size. This suggests the proper clothing of 
the reels, or rather of the scalping numbers, the flour numbers being 
practically arbitrary. 

Two diagrams are here given; one for the separation of middlings re¬ 
duced by rolls, and the other for the separation of middlings ground on 
buhrs. We will consider them in the order named. The first reel is 
clothed with Nos. 12, 6 and 4 cloths. Having adopted these numbers, 
the grinding must be accommodated to the scalping numbers. This 
grinding should be such as to require a portion of the stock which passes 
through the No. 4 cloth to be sent to the tailings. This is done by clos¬ 
ing slides to the point where it is desirable to carry off such stock, the 

(20) 


308 gradual reduction milling. 

other portion which passes through that number being sent to the dust 
middlings rolls. The amount of the stock passing through the No. 6 
cloth which it is desirable to send to dust middlings, may be controlled 
by closing such slides under this cloth as the stock requires, and thus 
pass it to an open slide over that portion of the bottom conveyor which 
runs to the tail of the reel, and then to the dust middlings. This will 
rarely be desirable in a soft wheat mill. On the contrary, it might some¬ 
times be necessary, in order to carry some of the stock passing through 
the No. 4 cloth into the reel below. 

The next reel, which is clothed with Nos. 12, 14 and 8 cloths, is the 
one from which most of the Hour will be taken. The tail of any inferior 
portion of the product of the No. 8 cloth will be sent to the dust mid¬ 
dlings. The cut-off from the flour, or a proportion of the product of 
the scalping number, is sent to the reel below. The cut off and tail of 

this reel are second middlings, as 
may be a portion of the product of 
the No. 8 on the reel above. Thus 
it will be seen that none of the mid¬ 
dlings coarser than those which will 
pass through a No. 8 cloth are sec- 
_ ^^>4—^ - r.uimgs. ^ on( j middlings, and any portion of 

^ ^ Dust Mids. suc h stoc k which the miller may 
choose may be sent to the dust mid¬ 
dlings, but if his middlings are well 
purified and the separations on the 
upper reel properly manipulated, the 
proportion of such stock will be very 
small indeed. It may be well to call 
attention to the fact that from thirty 
to thirty-six inches grinding surface 
are necessary for such stock—a pair 
of 18-inch rolls, say, for the finer 
middlings and a 12-inch for the coarser—though 18-inch for each might 
be better. They should make about 250 revolutions per minute. 

As to the separation of middlings ground on buhrs. The principal 
difference between one and the other is that the scalping numbers are 
finer, which fact makes it unnecessary to change the flour numbers. An¬ 
other thing which may be noticed is that a large proportion of the stock 




Dust Mids. 



(2h 

























GRADUAL REDUCTION MILLING. 


309 


may be sent to the tailings and dust middlings. One reason for the 
scalping numbers being finer is that the stock can be reduced much 
more rapidly; that is, with fewer reductions, on buhrsthan it can on rolls. 
This means as well that a larger proportion of the stock is reduced to 

fine particles. Another reason 
for these finer scalping numbers 
is that a larger proportion of the 
impurities are reduced in such a 
way as to endanger their being 
carried into the second middlings. 

There are two sides to this 
question of the reduction of mid¬ 
dlings by rolls or buhrs, and par¬ 
ticularly so in small mills. One 
is that the rolls make cleaner 
flour, and the other is that they 
make less of it on the sized plant 
which a 100-barrel mill justifies. 
To put it in another form, it may 
be said that the rolls make bet¬ 
ter, or cleaner flour, while in the 
case mentioned the buhrs make a 
cheaper flour. To take another view of this matter, the equipment for 
the purification of middlings cannot be so complete on a small mill as 
on a large one; that is, the expense of the plant is not justified by the 
returns. For this reason the middlings will not be as well purified in a 
small mill as in a large one, and thus their purification by rolls would 
partially atone—as to the quality of the flour produced—for the differ¬ 
ence in the quality of the original middlings. In the case of a larger 
mill, there is usually a more expensive proportional equipment of puri¬ 
fiers and sizing rolls, and for that reason it may be expected that there 
will be cleaner middlings, which are les-s liable to be injured on millstones 
than those of smaller mills. Thus it may be seen that this is a two 
sided question, whichever way it may be viewed. 

The quality of the second middlings may be estimated by consider¬ 
ing their history. The quality of the first middlings, their reduction, 
and the means adopted for their bolting, determine the character of the 
second middlings. If the first is not right, the second cannot be right. 






























310 GRADUAL REDUCTION MILLING. 

If we look into the history of the first middlings we may judge as to the 
excellence of the second middlings. If the first middlings are reason¬ 
ably well purified—if they are properly reduced and intelligently sepa¬ 
rated subsequent to their reduction—the quality of the second middlings 
may be considered, other things being equal, as being good—better than 
the first. The first middlings having been reduced so that they will pass 
through a No. 6 cloth and finer, that portion which is coarse having been 
sent to the dust middlings or the reduction which follows the second 
middlings, it is clearly to be seen that, considering the means of purifi¬ 
cation of the first middlings and the plan of their reduction, the second 
middlings will be clean and bright; that is, that portion which went 
through a No. 6 cloth and finer, previous to its reduction as second mid¬ 
dlings. Formerly the second middlings were purified on a separate sys¬ 
tem of machines, but if they are reduced on rolls in the manner pre¬ 
viously indicated, further purification is hardly necessary; and, if they 
are reduced on buhrs, further purification by the ordinary means is 
hardly possible. Not but that a most excellent reduction may be made 
on buhrs, when sufficient previous preparation of the middlings is made, 
but it is to be remembered that where such a reduction is made, the 
middlings must have been reduced to a small size in anticipation of a 
millstone reduction, and their purification well cared for. 

Thus it is to be seen that the second middlings are to be purified be¬ 
fore they become second middlings, and that whatever purification they 
get after their reduction as first middlings is by the first reels, during a 
process of bolting. If the milling operations have been properly car¬ 
ried forward, there is no reason why the second middlings should not 
yield the best flour in the mill. Their quantity will usually be less where 
the reduction of the first middlings has been made by millstones, though 
this may be regulated somewhat by the character of the grinding. Where 
there is ample capacity for the reduction of the second middlings, it is 
well that the quantity for reduction by the machinery for such middlings 
be maintained equal to the convenient reduction capacity of that ma¬ 
chinery, the reason for this being that the flour made with this end in 
view will be rounder and sharper, and in this way bear less evidence of 
haste in grinding. The middlings will be of better quality, as well as the 
flour. It is well that this feature be duly considered in the reduction of 
the middlings, in that middlings stock of good quality is the end sought 
in modern milling. For this reason it is fitting that such stock should 




GRADUAL REDUCTION MILLING. 


3 1 1 


be afforded the best and most careful reduction, which never means 
rapid reduction. 

The diagram for the reduction and separation of second middlings 
must be considered with reference to what has preceded it. While such 
an arrangement might be proper, in connection with previous directions, 
it might be altogether improper if applied in connection with different 
conditions. It is not possible to suggest arrangements of this kind which 

are suitable for the reduction and 
arrangement of a particular grade of 
stock, unless it be known what has 
gone before, and at the same time 
unless we anticipate what is to come. 

The scalping cloth on the tail of 
the first reel is shown as being No. 6. 
With hard wheat this will be finer, 
and it might be that the results would 
be better if No. 7 cloth were used in 
the present instance, soft wheat being 
considered. But, if the grinding 
were not exact, it is quite possible that 
such an arrangement would result in loss. Then No. 6 cloth is used, and 
the conveyor under it is shown as running to the tail. Thus any portion 
of the material which passes through the No. 6 may be sent to the tail¬ 
ings. At the same time it is altogether probable that a larger portion 
of this material will be sent to the reel below. It is to be remembered 
that the No. 6 cloth is placed on the tail of the first reel, presuming that 
the second middlings will be reduced on rolls. While it is true that a 
portion of this stock has passed through the No. 6 cloth, little or none 
of it that is coarser being run to the second middlings, it is true that, 
after its reduction as such middlings by the smooth rolls, a portion of it 
will tail over a cloth through which it would have passed previous to its 
reduction. This is an element which is not true of millstone reduction. 
This scalper, in such an instance, would require to be much finer, say 
No. 9 or 10 cloth. 























CHAPTER LVII. 


ALTERNATIVE METHOD FOR THE REDUCTION OF MIDDLINGS. 

The following is given as a suggestive sketch for the reduction and pu¬ 
rification of middlings for a ioo-barrel mill. The idea is to take the 
coarse middlings from the purifiers and treat them as first middlings, and 
the fine middlings from the first middlings, together with the midd.ings 
from the middlings—that is, the second—which two latter being run to¬ 
gether are treated as second middlings. Or, to express it more clearly, 
the coarse first middlings are treated as first middlings and the fine first 
middlings and second middlings are run together and treated as second 
middlings. The plan contemplates the reduction of the coarser first 
middlings—those which tail over a No. 3 cloth—by rolls, and the reduc¬ 
tion of the second middlings by millstones. Altogether, it is an ar¬ 
rangement which the writer likes very much. 

On the first reel which takes the reduced stock from the rolls a little 
fiour is taken off at the head, and the middlings are dusted over a No. 
6 cloth and scalped over a No. 4. Any portion of this No. 4 may be 
sent to the tailings, and the desirable portion of the product thereof, to¬ 
gether with that from the No. 6 cloth, is sent to the second reel, where 
more Hour is taken off, and where a separation is made over a No. 6 
cloth, which will allow a portion of the stock to go to the second 
middlings direct. Then most of the flour is taken oft' on the third reel, 
the material by the time it gets to that reel being in a splendid condi¬ 
tion from which to take flour. As may be noticed, it was first scalped 
over No. 4 and then again over a No. 8 and a No. 6 cloth, in a way to 
allow any proportion of the latter which may not be suitable to be sent 
in another direction as second middlings. Thus it is plainly to be seen 
that we will get most excellent flour from this reduction, the quality of 
the flour, according to the scalping arrangements, being entirely under 
the control of the miller. 

The quality of the second middlings is also controllable by the ar¬ 
rangements here outlined, it being possible to run stock which the miller 
does not care to purify, to the tailings. Again, on the second reel, the 







GRADUAL REDUCTION MILLING. 


3*3 


. Coarser Mids From Purifier. 



stock intended for the purifier is 
thoroughly well dusted; and if 
the reduction by the smooth rolls 
be of the proper quality, if these 
rolls have the proper amount of 
grinding surface, which is here 
allowed them, and if their reduc¬ 
tion be not too rapid, by setting 
the rolls too close, the middlings 
which are sent to the purifiers 
will be in most excellent condi¬ 
tion to come out in splendid 
shape. The clothing of this pu¬ 
rifier is indicated, the numbers 
being suggested by the clothing 
of the reels above. The mid¬ 
dlings were dusted over a No. 8 
cloth, and graded over a No. 4,. 
hence the head number is 8, and,, 
as it happens in this instance, the 
tail number is 4. It is a usual 
practice of the writer to make the 
tail number on the purifier one 
number coarser than the grading 
number on the reel or sieve, but r 
in this instance, it is desirable to 
keep up the stock as well as pos¬ 
sible, and to run any stock which 
will pass over the No. 4 to the 
tailings. This serves a double 
purpose; first in the purity of the 
stock from the sieve action, and 
second, in keeping the sieve cov¬ 
ered and thus getting the full 
benefit of the suction—a thing 
greatly desired in this instance. 

Two pairs of millstones, both 
of which will not be necessary, 
thus allowing time for going over 












































































GRADUAL REDUCTION MILLING. 


3 1 4 

the face occasionally, are shown in the diagram. As a matter of capac¬ 
ity, the difference in cost not being great, it is suggested that they be 
forty-eight inches in diameter. As to the quality of the stone, it should 
be close. The uniform draft of the furrows should be, say, six inches, 
more or less, depending on the speed, and with a large number of small 
lands and furrows, which should be faced, when necessary, with a dia¬ 
mond dresser, and never cracked, even with a diamond. They should 
be kept as smooth as possible. As before described, the millstones re¬ 
duce the second middlings and the fine first middlings. The tail of the 
No. 9 cloth goes to the tailings and the product of the No. 12 to the 
second reel. The cut-off and tail of this reel go to the dust middlings, 
which product will be considered next. 





CHAPTER LVIII. 


TAILINGS—PURIFICATION OF TAILINGS-TAILINGS ROLLS-SEPARATION OF 

THE TAILINGS PRODUCT. 

If one were to begin at the tailings rolls hopper and trace back, he 
would find reason to feel disturbed at what he saw; in the first place, 
because of the richness of a part of the stock, and again on account of 
the poorness and contaminating qualities of other material. In the first 
instance, we have middlings which are not good enough for patent Hour, 
and which we cannot but feel are too good for tailings. Then we have 
a large amount of fluffy stock which comes from the aspirators and the 
tails of the machines, which has just enough material in it to suggest 
nubs of middlings and white stock, so that we do not feel like running 
it into the red-dog. Here we have two extremes—stock which we can 
not run into the patent flour because it is hardly good enough, and ma¬ 
terial which we do not feel like running into the red-dog because it is 
hardly poor enough. Hence, and not logically, we run both together in 
the tailings rolls hopper. As we look at it in this way it seems a very 
strange and unreasonable proceeding. Of course we might separate 
the two in the reductions and boltings, but in a small mill we do not 
feel like keeping up all these divisions. One way out of this trouble 
has been outlined in the accompanying diagram, but it leaves another 
difficulty unsurmounted, and that is in the grinding of the stock. We 
have material as coarse as Nos. o and oo, and as fine as the product of 
a No. 4 cloth, going to a single pair of rolls. There is not a very large 
proportion of the extremes of the sizes indicated, but there is a toler¬ 
ably large proportion of the coarse stock and a smaller proportion of 
the fine stock. A setting of the rolls-which will properly reduce the lat¬ 
ter will flatten the former. On the other hand, if the rolls be set to re¬ 
duce the coarse stock properly, they will have very little influence on 
the finer material. In a large mill this problem is easily solved by grad¬ 
ing the tailings. In a small mill this cannot be done, as the volume of 
stock is not large enough to justify the use of two pairs of rolls. 

To return to the diagram: We have a sieve—the same kind which we 


3 l6 


GRADUAL REDUCTION MILLING. 

use in grading the middlings, only much smaller, say nineteen inches 
wide and ten feet long, which is clothed as indicated. To this is run all 
the tailings, the object being to get rid of the light, huffy material which 
is a part of all the stock which goes into the tailings. This is done in 
two ways: First by the sieve action, which will carry a large volume of 
this stock over the tail or through the coarse cloth at the tail; and second, 
by the action of the aspirators, which have been described so many 



Feed, 



Smooth. RoHs. 
9 x 12. 


— 12* Long-.- 


* > 





<« - 

-<—<*4 



times. This would be nothing more nor less than a tailings purifier. 
Any one who has never tried the experiment will be surprised at the 
large amount of red, fluffy stock which will pass over the tail of this ma¬ 
chine. It will be in such volumes that, as it reaches the tail, one can 
take up large handfuls of it without a grain of middlings. The aspira¬ 
tors will take out the finer portion of this material, and the suction can 
be so regulated that the stock shown as going to the feed will be poor 
and thin—nothing more than bran which is equally red on both sides 
















































GRADUAL REDUCTION MILLING. 


3 1 7 

This arrangement cannot be commended too highly. It is cheap, and 
can be made and set up by any ordinary mechanic. The top of the 
sieve should be left exposed so that it can be readily cleaned. This is 
best done by hand with the edge of a stiff leather belting. A cleaning 
once an hour, at most, is sufficient. 

The separation of the reduced stock is about the same as we have 
shown once before. This stock is scalped on Nos. 7 and 3 cloth. The 
undesirable portion at or near the tail of the No. 7 is sent to the 
second dust middlings, or, if the stock at the tail of No. 3 should be ex¬ 
tremely poor, it may be sent to the bran duster by closing slides under 
the tail of the top conveyor. The writer does not mean to say that he 
would run this material in with the bran to the duster, as he does not 
think that anything will be gained by the use of the bran duster on bran 
after it has left a centrifugal scalper. But we will consider this later. 
The cut-off from No. 7 and the desirable portion of the product of No. 
4 is sent to the dust middlings reduction. By the way, it might be 
well to use a No. 2 instead of a No. 3 on this tail cloth, on soft wheat. 

The better portion of the product of No. 7 goes to the reel below. 
The cut-off from the flour cloth and a part of the No. 6 goes to the first 
dust middlings. If this tailings purifier was not used, this could not be 
done; the product, of the No. 6 would be entirely too red. The tail 
of No. 6 would be light and thin, having been scalped through a No. 7 
before. 


CHAPTER LIX. 


DUST MIDDLINGS-PRODUCTION OF DUST MIDDLINGS—REDUCTION OF DUST 

MIDDLINGS—ALTERNATIVE METHODS FOR THE REDUCTION OF DUST 

MIDDLINGS. 

During the years immediately succeeding the introduction of purifi¬ 
ers, very fine cloth was frequently used for dust middlings. The writer 
remembers to have seen the advertisement of a prominent American 
purifier in an English journal, wherein it was claimed they could purify 
middlings dusted over Nos. 14 and 16 cloths. About the same thing 
was often undertaken here. No. 12 was the common dusting cloth pre¬ 
vious to the introduction of gradual reduction methods. At least this 
was so in the winter wheat section. No. 10 cloth was used in a few in¬ 
stances, though it can hardly be said that this was recognized as being 
the correct thing at that time. The dustings from the reels mentioned 
above were pretty hard looking stock; it was fiat and feathery. With 
the introduction of the roller system, the middlings were dusted over a 
coarser cloth—No. 8 or 9 mostly—but the principal thing which distin¬ 
guished this method of dusting from that of earlier years, was that it was 
done entirely before flour was taken off, rather than after, and the dust¬ 
ing reel was done away with. One thing which made this possible, aside 
from the fact that the dusting cloth is coarser, is that there are more mid¬ 
dlings and less dust by the roller system of reduction. Again, the mid¬ 
dlings by the latter method are coarser, and, because of their size and 
weight in the reel, facilitate the operation of dusting. To illustrate this 
difference, attention is called to the proportion of flour in the middlings 
as made by millstones. No. o middlings on soft wheat were commonly 
the coarsest legitimate middlings made, and there was a very large pro¬ 
portion of fine middlings. It is easy to remember that in the winter 
wheat section, No. 6 cloth was the ordinary grading number which sep¬ 
arated the coarse from the fine middlings, and that in a mill which had 
three runs of buhrs grinding first middlings, there would be one for coarse 
and two for fine, and at a time when the sizings rolls were not used. 


GRADUAL REDUCTION MILLING. 


3 r 9 


Now we know that No. oooo middlings are by no means uncommon. 
However, No. oooo stock is not legitimate middlings, but simply nubs 
of wheat largely covered with bran. But, in any event, the proportion 
of coarse middlings is very large. In the millstone mills which changed 
to rolls and maintained the old method of grading middlings—that is, 
from coarse to fine—they found that they had to change the No. 6 cloth 
and replace it with a No. 4, or even a No. 3, to give their fine machines 
anything to do. 

This large proportion of coarse middlings has a great deal to do with 
the ease of dusting. With the reel covered with the No. 8 or No. 9 
cloth, the separation of the flour from the middlings is soon made. The 
plan of using this coarse number is justified by the results in purification. 
At the same time that it is a better method with reference to the first 
middlings, it creates a new stock, a new classification, another grade 
of middlings—a stock which invites a different handling from any which 
we have yet considered in this 100-barrel mill. Dust middlings, as we 
will call this material, is that stock which is neither flour nor middlings 
which can be purified by the ordinary methods. It is material which 
will pass through the No. 8 and No. 9 cloth of the middlings scalper, 
but which will not pass through the flour cloth; that is, it is material 
which will pass through the Nos. 8 and 9 and tail over the Nos. 12 and 14. 

In the diagram for the reduction of the second middlings, it will be 
remembered that the better portion of the unreduced material—that is, 
the middlings from the second middlings—was run into the dust mid¬ 
dlings. The stock mentioned is virtually third middlings. It is better 
in quality than the dust middlings proper, but in a mill of this size the 
quantity is too small to admit of distinct and separate reductions and 
separations. But these third middlings are of the same size as the dust 
middlings, and in other respects suited for reduction therewith, the only 
difference between the two stocks being that the latter has been submit¬ 
ted to a greater number of smooth roll reductions than the dust mid¬ 
dlings, and therefore is not so susceptible to the action of the rolls; 
that is, the rolls do not have so much influence on the third middlings 
as on the other stock. It is well known that after material has been re¬ 
duced a number of times without disintegration of any kind on smooth 
rolls, the latter reductions have less influence on it—reduce it less—than 
the first. 


3 2 ° 


GRADUAL REDUCTION MILLING. 


Strenuous efforts were made to purify the dust middlings stock during 
the earlier times of its development. In the first place, the purifiers 
had very little effect upon it, and that little was wastefully secured. With 
good grinding on the break stock this is a good material, and it is espe¬ 
cially bright and clear in soft wheat mills. This stock has been ground 
on buhrs, but there is nothing half so good for its reduction as the smooth 
iron rolls. They, in connection with the reels which follow, are about 
all the purifiers needed, and are certainly all which would avail anything 
in the handling of these middlings. The flour made is next to the patent 
in quality. The diagrams offer two suggestions for the reduction and 
separation of this material. The first is with two reels, and the second 
with one. As to the first, the reels are only twelve feet long, which is 

sufficient, considering the size of 
the mill. Two such shoit reels 
present ample bolting surface and 
make the proper classifications. 
The first reel, it may be noticed, 
is clothed with No. 7 at the tail. 

__ To those who have not studied 

n °12 No 14 | ^ its stock and its reduction care- 

fully, this number would appear 
illogical when it is remembered 


Suggestion where 2 ReciS a.e used. 

. 0.0 9 x 18 Smooth Iron. 

1st Dust ]Vlids Rolls.' 

12 Ft Long. 


No 12 


No 7 


y\oWf* 


-<r~<4r 













T °2D 

Suggestion where one Reel is used. 


oo !_ 


14 Ft Long. 


9 x 18 Smooth Iron. 
1st Dust Mids Rolls. 


No 12 No 13 


No 6 


-f tortf* 



,lld A/u,s Iiccl ‘ or igi na l stock all passed 

through No. 8 or 9 cloth. But one 
quality of this material is that it 
is inclined to be a little flat, and 
is made so by ever so careful a 
reduction. It does not neces- 


T °2l), 


77 s sarily cake, but is merely broad 
rf01 in the distinct granules. Again, 

this material, when passed through the Nos. 8 and 9 cloth, was assisted 
in its bolting by some very coarse material, and for that reason would, 
when by itself, tail over a cloth coarser than that through which it orig¬ 
inally passed. 

The quality of the tail of this reel can be regulated in the usual way, 
by closing or opening slides under that portion of the upper conveyor 
which runs to the tail. Phis arrangement admits of running any por- 
































GRADUAL REDUCTION MILLING. 


3 2 1 


tion of the product of the No. 7 to the tailings of the reel below. More 
time and space is taken in the description of the scalping cloths and the 
disposition of the stock derived from them than is devoted to the dour 
numbers, because it is so much more important. These flour numbers 
are influenced for good or bad by the arrangement of the scalpers and 
scalped product. The diagram is self-explanatory to such a degree as 
to need no further explanation. 


CHAPTER LX. 


REDUCTION AND SEPARATION OF SECOND DUST MIDDLINGS-ALTERNATIVE 

METHODS OF SEPARATION. 

Before going to the consideration of the diagrams given, it is well to 
consider in short form, the effect which the reduction by rolls may have 
on stock which has reached this stage. It is particularly true of soft 
wheat that, after material has been reduced a certain number of times, 
an equal number of following reductions will not reduce the stock as 
much as the first ; or, to express it more clearly, of four smooth roll re¬ 
ductions, the first two do proportionally a great deal more in the way of 
finishing the stock than do the last two. We find material going to the 
rolls for the reduction of the second dust middlings of a class which has 
been repeatedly treated on smooth rolls. While the writer does not be¬ 
lieve in a class of reductions which cake the material to an appreciable 
extent, he does know that there is a certain battening of the material, 
which makes it very difficult for roller reductions to handle. A mill¬ 
stone would do good work on this stock, and, if the grinding were not 
too low, would make good Hour. For such stock the millstones should 
be smooth. We have a compensating device in the action of the cen¬ 
trifugal reel in rendering this material separable, and at the same time 
leaving it in a condition to be thoroughly susceptible to the influence of 
roller reductions. This is regarded as one of the legitimate uses of the 
centrifugal reel, its influence being such as to take advantage of the 
forms given the stock which will render the good separable from the bad. 
Another point favorable to the centrifugal reel at this stage of the oper¬ 
ation, is that it will bolt the material which may be in such a condition 
as to be difficult of handling on the ordinary reel. It avoids the use of 
coarse cloth, brushes and wipers, and other instruments for evil. Two 
suggestions are given for the reduction and separation of this material— 
that is, the second dust middlings—the second of which is preferable, a 
centrifugal reel being used in connection with the smooth iron rolls. In 
Fig. i, where an ordinary reel is used, Nos. 12 and 14 are used for the 
flour numbers, and No. 4 for the scalping number. The tail and the 


GRADUAL REDUCTION MILLING. 


-> 'y i 


Smooth Rolls 
12 inch Dong - . 

2nd Dust Mids. 


inferior portion of the product of the No. 4 may be sent to the second 
red-dog reduction. The flour may go to the clear and the cut-off, and 
the better portion of the product of the No. 4 goes to the first red-dog 

reduction. The quality of the 
flour made at this operation will 
depend largely on the character 
of the reduction by the rolls. It 
is important that the material be 
reduced to, as nearly as possible, 
a uniform degree of fineness. For, 
if any portion of unreduced ma¬ 
terial gets through the rolls, the 
Fig. 1 . * flour cannot but be gray and 

specky. The closing of slides will have very little effect on the flour 
numbers. 

The second and preferred suggestion, as shown in Fig. 2, is arranged 

on the same general scheme as 



2t >(I p 


Smooth Rolls 
12 inch Long - . 


2nd Dust Mids. 


Centrifugal Reel (5 Ft i-ong. 






10 14 

5 


/ ZV 

1 

— —^' rr r 

-»—^- 



Fig. 2 . 


the first. Because of a centrif¬ 
ugal reel being used, the scalp¬ 
ing number is finer, as well as the 
first flour number. With this plan, 
the stock going to the red-dog re¬ 
duction will not be so rich or so 
large in volume as by the first. 
Consequently there need not be 


so much milling after the material has left this reel. 

















« 


CHAPTER LXI. 

RED-DOG REDUCTION BY SMOOTH ROLLS—DIAGRAM OF SEPARATION OF 

RKD-DOG STOCK. 

The reduction of red-dog stock by rolls is the next thing in order. It 
is nearly an endless piece of work. In some of the other diagrams 
which are to follow, millstone reductions will be shown, but for the pur¬ 
pose of making a showing for a roller 
method the following is given, and it 
will accomplish the work which it is 
intended to do. 

Smooth rolls are natural purifiers. 
Their tendency is to reduce the Hour 
stock, and to either flatten out the 
impurities in such a way as to render 
them separable from the Hour, as is 
the case with the germ and fibrous 
and cellular structure of the wheat, 
or to leave other impurities intact— 
that is, whole—as may be in the case 
of bran, or other material of like 
character. We take all such mate¬ 
rial, excluding the bulk of the bran, 
run it together and call it red-dog, 
and then we take this same material 
which the rolls have failed to reduce 
before and send it to the red dog 
rolls. Of course, they do it very 
little good. We have white, flat 
stock going to the feed pile. It is 
this condition of things which so fre¬ 
quently brings in a pair of buhrs at the tail end of the mill, and it is as 
disintegrators and grinders that these buhrs do their work. Red-dog 
Hour is, or should be, made from the impurities extracted from other flour 













































GRADUAL REDUCTION MILLING. 


stock, and in their nature the qualities which made them separable by 
roller reduction prevents them from being fully reduced by the red-dog 
rolls, however great may be the number of reductions. If this is true, 
it strikes the writer that the rolls themselves will not sufficiently reduce 
the red-dog material, except, perhaps, with an unusually and unjusti¬ 
fiably large and expensive plant. The writer has attempted to reduce 
red-dog with smooth rolls, and has employed as many as four reductions 
for such a purpose, though his faith in the ultimate result was never so 
great but that he had a millstone at the tail end. This was on soft 
wheat, the red dog from which is always more difficult of reduction than 
that from hard wheat. 

Now, as a short and direct method of reducing the red-dog stock, it 
is suggested that, after its first reduction and separation in the manner 
indicated by the diagram, the tail of the reel be passed through a bran 
duster clothed with, say, No. 72 wire. Into this same duster would 
also go the stock from the other parts of the mill intended for the last 
reduction of the red-dog. The tail of the duster would be sent to the 
feed pile, while the product, after being bolted on the centrifugal reel, 
would have the coarser stock sent to the last reduction of the red-d; g. 
Thus this material would have all the coarser bran stocks separated from 
it, all the fibre and white stock disintegrated and the flour removed there¬ 
from, and, altogether, be in a favorable condition to be acted upon by 
the red-dog rolls. The product of these rolls, as indicated, is sent to a 
centrifugal reel, and the tail of that reel to a finely clothed bran duster, 
and finally to the feed. 

Following is given the completed diagram of the 100-barrel mill 
which has been described in the foregoing chapters. 











































































• 










































































































































































































































































































































































































































































































































A SEVENTY BARREL MILL. 










CHAPTER EXII. 


WHEAT CLEANING FOR A 70-BARkEL MILL—CAPACITY OF WHEAT CLEANING 
MACHINES-SEPARATION OF DUST AT THE WEIGH HOPPER—THE ROLL¬ 
ING SCREEN-ROLLING SCREEN AS A SEPARATOR—COCKLE SEPARATOR 

-SCOURING MACHINE. 

Before considering the diagram of this 70-barrel mill, it will be well to 
say something definitely about the wheat cleaning. In a mill making 
seventy barrels of flour in twenty-four hours, using four and a half bushels 
of wheat to the barrel, there would be required 315 bushels of wheat 
during that time. This is sufficiently accurate for determining the 
amount of wheat cleaning machinery needed. It will be presumed that 
we do not care to run the wheat cleaning machinery all the time. Most 
millers prefer to clean enough wheat during the day to last all night. If 
the wheat cleaning machinery is to do all of its work in ten hours, the 
various machines would have to be selected on a basis of between thirty- 
one and thirty-two bushels per hour. As all machines are not numbered 
alike, it will be presumed that a selection would have to be made on a 
basis of between thirty-one and forty-five bushels an hour, or in that im¬ 
mediate range. It is desirable that the estimate be made as nearly as 
possible on the minimum capacity of the machines. If the calculation 
should show that forty bushels an hour were required, the writer would 
rather advise the use of a machine whose minimum capacity was forty- 
five bushels an hour than one whose maximum capacity was that amount. 

As the wheat is taken into the mill, a good thing to do, as said before, is 
to have a suction so arranged as to take off the dust which may arise in 
discharging the wheat from the cars or wagons into the scale hopper. 
Where the scale hopper is located in the mill, as it nearly always is in 
small mills, as well as in many large ones, the dust arising from the 
wheat is sufficient to penetrate everything in the immediate vicinity. 
The arrangement for collecting the dust, or rather drawing off the ma¬ 
terial which may arise, need not be too elaborate; in fact, it should not 
be other than a very simple arrangement. In the event of any compli¬ 
cations which might not be understood by those not used to machinery, 


334 GRADUAL REDUCTION MILLING. 

it would prejudice them unfavorably in their judgment as to the accu¬ 
racy of the weighing apparatus of a mill which contains such compli¬ 
cated or unusual devices in immediate proximity to the scales. A sim¬ 
ple galvanized iron funnel placed over the shute and connected with the 
suction fan, will do all that is desired at this stage of the process. 

After discharging the wheat into the bins, we would arrange to have 
it pass through a rolling screen before going to the separator. This 
screen should be as long as convenient ; eight feet would be the mini¬ 
mum length and eighteen the maximum. The extra length is desirable 
because of its scouring influence on the grain. This screen might be 
clothed with No. 12 wire for about five feet at one end and No. 6 wire for 
about three feet at the other end, the dirt which goes through the No. 
12 wire going out one way, and the wheat that passes through the No. 
6 the other. The tail of the No. 6 wire, consisting of dirt, straw, etc., 
would go out at the same end as the wheat, but should, of course, be 
kept separate. There should be a suction fan in connection with this 
rolling screen which would carry out all the natural dirt, and that which 
is the result of the scouring. Attention has before been called to the 
fact that, while the rolling screen does good work, it was discarded with 
the influx of new machinery—in the change from the older to the newer 
processes of milling. In order to emphasize the value of this machine, 
it is well to mention that they are u*ed in Hungarian mills not only for 
the purpose of wheat cleaning, but for grading as well. In some of 
these mills, during the process of wheat cleaning, the wheat is graded 
into large and small wheat before going to the separators. The smaller 
the stream of wheat running to these screens the better will be the 
work of scouring. This is apparent when we consider that when only a 
small quantity of grain is in the reel, each grain will be more often in 
absolute contact with the screen, will be subjected to more friction than 
where there is a larger amount of wheat to be taken care of. 

It was common to use the old rolling screen largely for the purpose 
of separating screenings without particular reference to the separation 
of straw and corn, and other large impurities, though the writer remem¬ 
bers, in a few instances, where a coarse piece of wire was used in the 
manner here described. He also remembers to have seen one such 
screen running in 1862 and 1863, which was placed in a room in a base¬ 
ment. There was a box or hopper which would hold four or five bushels, 
located immediately over it on the giinding floor. In this box wheat 




GRADUAL REDUCTION MILLING. 


335 


was mixed. There were three spouts which entered it—one for amber, 
one for white, and another for long berried Mediterranean. At that 
time there was a premium of ten cents a bushel on white wheat, and 
from five to eight cents on amber. This wheat entered the screen, and 
the screenings which passed through the wire fell on the floor of the 
screen room, and as it filled up it was sacked from time to time and 
passed over a fanning mill, which, instead of being run by hand, was 
provided with a pulley that was run from another one attached to the 
projecting shaft from an elevator boot. From this screening the miller 
was able to get a little small wheat, which from time to time he ground 
into a separate grade of flour. The only other cleaning machine in the 
mill was a Eureka smutter. 

In considering the wheat cleaning in this 70-barrel mill, we will start 
with the idea that we are to do the work well—as well as can be done 
with the ordinary machinery which is at hand. The separator, which 
may be any of the first-class machines now manufactured, and of the 
size indicated at the beginning of this chapter, will follow the rolling 
screen. The wheat, having passed through the latter machine, will be 
in most excellent condition to be cared for by the separator. A good 
portion of its work will have been done by the screen, and, when it comes 
to the treatment of the wheat by the separator, the miller will find that 
he can make much nicer distinctions and do much finer work than when 
the separator had all of the work to do. In sections of the country 
where there is cockle, it will be well to follow the separator with a cockle 
machine, and, while it is necessary that no machine should be crowded, 
it is imperative that the cockle machine, of all others, should be given 
only the proper amount of work to do. The loss where the other course 
is pursued is quite apparent. There are combinations which include a 
separator for dust, oats, chess, etc., constructed in combination with the 
cockle separator, and in a mill of this size where there is cockle with 
which to contend, it might be well to use such a machine. 

Following this separation comes the scouring machine. To empha¬ 
size the matter of capacity, attention is again called to the fact that the 
scouring machines, as a part of the wheat cleaning machinery, are great 
sufferers from being overworked. In this mill the writer would use two 
scouring machines—the first one with beaters ot a mild type, and the 
second a brush machine. A scouring machine will come about as near 
running itself as any machine in the mill. The makers have been com- 


336 'GRADUAL, iREDUCTION MILLING. 

pelled to construct them with this idea. The fact that they will run with 
little care is no reason that they should be left to run themselves. Scour¬ 
ing machines are deserving of the same care, of the same judgment, and 
the exercise of the same skill, as any other machine in the mill. There 
are many millers who never use the lighter screw of the smutter or brush 
machine. They run along as they are started, without skillful care or 
attention. Very few millers consider it worth while to lay claim to skill 
in wheat cleaning; they are anxious to be considered experts in other 
•departments in the mill, but are indifferent as to this. 





CHAPTER EXIII. 


FIRST BREAK FOR 70-BARREL MILL-DISC MACHINE-SECOND BREAK- 

THIRD AND FOURTH BREAKS. 

The following cut shows the direction of the stock in the reductions 
and separations of this 70-barrel mill. 

The No. 70 wire at the head of the first scalper, which reel may be 
six feet long in this instance, separates whatever flour and du^t may be 
made by the wheat reduction. The middlings will go over the No. 22 
wire and the reel will tail over to the second break in the usual manner. 
The No. 70 wire is equal to about No. 6 cloth, and the stock which 
goes through it will be subject for the low grade. The only objection¬ 
able feature in this arrangement is 
that the semirings on the No. 22 wire 
run in with the middlings. As far 
.as the first break Hour is concerned, 
the method of taking only that portion 
of the material which goes through 
the No. 70 wire into the flour reel, is 
preferable to sending the entire pro¬ 
duct, say of the No. 22 wire or coarser, as is the usual method, into that 
flour reel. The heavy, coarse middlings whip out the cloth and make it 
impossible to get even a fair quality of flour. The stock is so sharp that 
it cannot bolt clean, and then the friction of the middlings is not desir¬ 
able. It tends to pulverizing, and to run what would otherwise be pat¬ 
ent flour into the low grade. With our arrangement, we send the mid¬ 
dlings which pass over the No. 70 wire and through the No. 22 wire to 
the grader, thus avoiding unusual and Undue friction to these middlings. 

The clothing of the scalper with No. 22 wire is unusual, No. 18 wire 
being the accepted clothing for that reel. But, as explained before, No. 
18 wire equals No. 0000 silk, and No. 0000 middlings have no business 
in any mill unless there are especial provisions for taking care of them 
in a manner entirely separate and distinct from the other middlings. No. 
22 wire is equal to No. 000 silk, which middlings are a little large for a 

















33 $ 


GRADUAL REDUCTION MILLING. 


mill of this size. The product of the No. 70 wire, as shown, is rebolted 
on Nos. 12, 14 and 16 cloth. This cloth is so arranged that it will 
hardly be desirable to make a cut-off on a short reel, say one of ten feet 
in length. It is not unusual to clothe the first break scalper with a piece 
of No. 90 wire at the head, and then run the product into the red dog 
reel; bur, as No. 90 wire is equal to No. 8 cloth, it is clear that the dif- 
ference between the number on the low grade reel and a No. 8 cloth 
will escape reduction and thus go into the feed, which is wasteful. 

The writer has never seen a first break by rolls which was as good or 
a^ satisfactory as that made by a disc mill, and he is surprised that these 
machines are not in more general use in large mills. The first break by 
rolls is far from satisfactory. While the idea is to split the wheat, there 
are a large muni er of grains which are not split in the proper way, and 
quite a proportion of grains which are mutilated. With the disc mills 
this latter proportion is largely reduced, though the proportion of first 
break flour is increased. The second and following breaks are much 
better when the wheat is split than when broken in an irregular way, as 
is so commonly the case with roller first breaks. 

The ideal of gradual reduction would be something like this: Exact 
splitting of the wheat on the first break; the detaching of a large por¬ 
tion of the middlings on the second, and, perhaps, a slight breaking of 
the wheat ; the detaching of a larger portion of middlings on the third 
and fourth breaks, without an absolute breaking of wheat or bran during 
such operations. On a six break mill, the fifth break is the beginning of 
the bran cleaning operations, and has in mind the scraping of the re¬ 
maining Hour and middlings from the bran. The sixth is the finishing 
operation. All this matter which pertains to the size of the bran is not 
practicable in regular milling, but the nearer we come to splitting the 
wheat on the first break, the smaller the proportion of broken and lacer¬ 
ated grains—grains which have the backs, ends and sides knocked off-— 
the more nearly will we reach this ideal as to the size of the bran par¬ 
ticles. 

In the earlier descriptions of the gradual reduction method it will be 
remembered that the idea was conveyed that it was a gradual breaking 
system, and the name break rolls would imply the same at the present 
time. If the mere breaking of the wheat was the proper plan, it might 
be possible to cut it into small particles, and at the same time make a 
smaller proportion of fiour than by doing the same with rolls. Hut such 




GRADUAL REDUCTION MILLING. 


339 


is not the idea or practice in gradual reduction milling. After the 
first break it is more like a gradual scraping process than a gradual 
breaking one. The middlings are gradually scraped from the bran. 
It is done gradually in order to prevent the making of a large quantity 

of flour, or the pulverization of the 


"Second Break. 

(^) ^ 9x12 Rolls, 12 Corrugations. 


22 W ire. 


'Third Break. 

CO 

M 

i 


-<«*- 




16 Corruga'’<>ns 9x18 Rolls. 


22 Wire. 


Tou c h Break. 


<< - 


QC 18 Corrugations 9x18 Rolls. 


Ij 


26 Wire. 





bran. In the nature of things a 
certain proportion of Hour will be 
made, a certain proportion of bran 
will be pulverized, and a certain 
other proportion of middlings will 
contain adhering portions of bran. 
We may consider the ideal of grad¬ 
ual reduction in order that we may 
estimate our failures, and, in doing 
so, we are necessarily influenced in 
the proper direction. 

The accompanying cut is a dia¬ 
gram of the second, third and fourth 
breaks, together with the Hour and 
middlings separation of the same. 

The second break is given twelve 
corrugations. It may be remem¬ 
bered that, in the course of this 
work, ten corrugations have been 
recommended for this break, but 
that number was used where the mill 
was larger and more elaborate. For 
the reason that we do not care to 
make a very large proportion of 
large middlings here, the size of the 
corrugations will be reduced. As has 

_ been stated before, the size of the 

Bast Middlings corrugations influences the size of 

the middlings. When the wheat is soft and the bran tough, it may be a 
proper thing to make a little closer reduction on the first and second 
breaks than would be in order under other circumstances. This was done 
for the purpose of being able to grind lighter—more open—on the third 
and fourth breaks, and, at the same time, be able to finish on the fifth 



Reel 12 ft. long. 


No. 9 Cloth. 


-i - IH- 



Centrifngal. 


12. 14. 16. 


Break. 

Flour 


Tail, to Bust Middlings. 
—TVS—-- 


->- 






































340 


GRADUAL REDUCTION MILLING. 

or sixth break. With soft wheat, if the effort be made to grind more- 
closely on the third and fourth breaks than would be necessary if the 
grinding had been advanced on the first and second, the middlings would; 
be soft and more difficult of purification than under more favorable cir¬ 
cumstances. Furthermore, the close grinding of the third and fourth 
breaks will yield a larger proportion of soft flour than is desirable. It 
is hardly possible to make a very large proportion of break flour with 
the coarse corrugated rolls on the first and second breaks. Thus, under 
the circumstances mentioned, it is not at all out of place to grind a little 
close on these two breaks, and there may be lighter grinding on the 
third and fourth breaks, with the idea of making clean, bright middlings 
with a small proportion of break Hour. According to the diagram given, 
the third break has No. 22 wire for the reel and sixteen corrugations for 
the roll, and the fourth eighteen corrugations for the roll and No. 26 
wire for the reel. It is on these two breaks that the best break flour 
and middlings are made. The degree of excellence, as implied before, 
is dependent largely upon the previous preparation of the stock before 
going to these rolls, and is repeated here for the purpose of emphasis. 
But, this preparation having been made,'there is an opportunity for nice 
discrimination and the exercise of judgment in the setting of these third 
and fourth break rolls. 



CHAPTER EXIT. 


DUSTING OF MIDDLINGS-EARLIER AND LATER METHODS OK MIDDLINGS' 

DUSTING COMPARED—BOLTING OF BREAK. FLOUR—USE OF CENTRIFU¬ 
GALS FOR THE BOLTING OF BREAK FLOUR. 

With the old stone methods only a part of the middlings to be puri¬ 
fied were removed previous to the dour separation. Some of the coarser 
ones were taken off at the first and fine middlings were taken out from 
the last reel. It was not an uncommon thing for the middlings dour 
stock and all to pass into the first Hour reel, and to take out flour at this 
stage of the process. On the tail of the reel was a scalper which sepa¬ 
rated a certain proportion of the coarse middlings, and, as said before, 
from the last dour reel was taken the fine middlings. This method is 
practiced to some extent in roller mills, but it is a custom which is be¬ 
coming less common all the time. It is entirely possible to thoroughly 
dust the middlings from the breaks over a No. 9 cloth, when all of the 
middlings are run into that reel. If the coarser middlings were removed, 
there might be some difficulty in dusting the fine middlings over such a 
cloth when the wheat is soft, but with the Larger middlings in the reel 
there can be no question as to the results. 

Not only is it desirable to dust the middlings in this way on account 
of the middlings themselves, but on account of the quality of the break 
dour, and the quality of the dour from the dust of such middlings. As 
long as there are coarse particles in a reel from which it is intended to 
make dour, it may be set down as a fact that the dour product is not of 
as good quality as it might be under more favorable circumstances. For 
this reason all dour stock should be scalped of all coarse material before 
endeavoring to make a dour separation. There are two reasons for 
using a No. 9 cloth in case of a middlings break scalper. In the first 
place; No. 9 cloth is as fine as should be used for dusting middlings pre¬ 
vious to purification. No. 8 cloth is in common use for this purpose 
and with reference to the size of the middlings. Another reason for 
using this No. 9 cloth is that it properly prepares the dour stock for 
bolting. This stock will bolt finer, cleaner Hour than if it had come 


342 


GRADUAL REDUCTION MILLING. 


through a cloth a degree Coarser. Stock which would pass through a 
No. 9 cloth in the days of stone milling could hardly be bolted on a flour 
reel ; it would be entirely too soft. For that reason coarser numbers 
were used for making a flour separation. The writer has in mind a case 
where the coarse middlings were dusted over a No. 6 cloth and then 
sent to the purifier, while the fine middlings were scalped a little from 
time to time as the stock passed from reel to reel, and the entire product 
of the fine middlings was dusted over a fine cloth. 

A larger number of reels were used in the days of stone milling for the 
purpose of dusting the first, or what would now be called the break flour, 
than at the present time. There were two reasons for this: First, there 
was more flour; and second, the stock was softer, less sharp in charac¬ 
ter. It was not an uncommon thing to use six and eight reels in making 
a separation from this grade of stock on a 300-barrel mill. From a 500- 
barrel mill the flour separation after the middlings have been scalped is 
frequently made on two reels clothed with Nos. 12 and 14 cloth. While 
it may be desirable in such a mill to have more reels, it is nevertheless a 
fact that the above condition of things is by no means infrequent. In 
the case of a 70-barrel mill, scalping reels for the middlings should be 
about twelve feet long. The tail of that reel would go to the middlings 
reel and the product of the centrifugal immediately under it. It might 
be well to have an extra conveyor under this scalper, which lower con¬ 
veyor would connect with the dust middlings roll. The reason for such 
an arrangement is this: If the flour stock should all be separated before 
the tail of the reel is reached, there would be clear middlings passing 
through the remaining portion of the tail of this reel, which middlings it 
would be desirable to send to the dust middlings, and which it would not 
be desirable to send to the flour reel. This flour reel, it will be noticed, 
is a centrifugal. A centrifugal is especially well adapted for bolting on 
a mill of this size. In the first place, if it be properly clothed, it will 
bolt the flour clean and bright, and it does it economically, in that the 
separation may be made on a single reel with a small expense for power 
and room. The separation of this stock can be made on one reel rather 
than two; it is all the better that it should be so done. After stock has 
passed through No. 9 cloth, very little opportunity remains for scalping, 
which would be the only reason for passing this stock through more than 
one reel. It will be noticed that this centrifugal is clothed with Nos. 12, 
14 and 16 cloth. On an ordinary reel, as a general thing, the writer 




gradual reduction milling. 


343 


does not care to use a cloth as fine as a No. 16, but, where a centrifugal 
is used, and especially at its tail, a No. 16 cloth means.a little finer as 
to the quality and softness of the Hour which passes through it than does 
the No. 12 at the head. The clothing of a reel in this way is not un¬ 
common in Hungarian mills. Under ordinary circumstances it would 
be entirely possible to take Hour the entire length of the -reel, which 
would be, say, six feet long. 

The fiour which is made at this stage of the process, on the reel re¬ 
ferred to, is of most excellent quality—a quality rarely understood or 
appreciated. The break Hour is pulled down in quality, is depreciated 
by the lower products, by the product of the reductions which come im¬ 
mediately previous to the low grade flour. There is a large amount of 
false pride and ignorance displayed in regard to low grade Hour. There 
is a disposition among millers to see how small a quantity of low grade 
Hour they can pack. It is all right to strive to clean the wheat, to make 
reductions so that the flour will not be contaminated by low grade prod¬ 
ucts, but when it comes to reducing and bolting the stock distinctively 
in a way to avoid the production of low grade flour on the low end of 
the mill, it is wrong and suicidal. It amounts to the destruction of a 
large quantity of what would otherwise be high grade flour. High grade 
flour can be made up to a certain point in every mill; in some mills the 
process can be carried farther than in others. Nevertheless, there is a 
limit. Whenever this limit is passed, it amounts to running low grade 
flour into the high grade packers. The thing to do in all milling opera¬ 
tions is, in the first place, to make all the high grade flour possible, and 
when the limit of such possibility is reached, to work for the sole pur¬ 
pose of making all the low grade possible. 

To return to the question of the break flour: It is well to say here 
that a miller will find it profitable to make a separate and distinct sepa¬ 
ration of the flour from the reel. If it does not show white and clean 
in the dough—does not make a most excellent quality of bread—the 
miller may set it down that there is something wrong in his bolting sys¬ 
tem. The doughing of the products of the various reels, when it is 
possible, is a practice which cannot be too highly recommended. It 
will give the miller an intimate knowledge of the various details and 
products of his bolting. 


(22) 


CHAPTER LXV. 


on 


First Dust Mid's; 
Px8 Smooth T r cn, 


Centrifugal 


REDUCTION OF DUST MIDDLINGS-SEPARATION OF REDUCED STOCK BV 

CENTRIFUGAL REELS. 

It has been the custom in following the stock through the mill, as has 
been done several times in this work, to take up the middlings purifica¬ 
tion immediately subsequent to the treatment of the break Hour reels, 
and to leave the dust middlings for consideration after the second mid¬ 
dlings have been cared for. In this instance, as a variation and for con¬ 
venience, we will take up the dust middlings first. It will be remem¬ 
bered that the last diagram had to do with the separation of the break 

_ Hour from the middlings to be 

Dust Mids. Reductions and Separations . r . . . . ... 

purified and the dust middlings. 

Here is a cut to which reference 
will be made in the course of 
this description. 

During the times of stone mill¬ 
ing there were, practically, no 
dust middlings. Anything which 
would not go through a No. 12 
cloth was middlings proper, and 
00 0x8 Smooth Iron Rolls Second Dmtaiids was se nt to the purifiers to be 

purified. In place of the dust 
middlings was what was known 
as dustings, a stock comparing, 
in a measure, with the cut-off 
from the last chop reel, and 
treated in the same way, which 
was frequently to rebolt and then 
to reduce on smooth rolls. It will be remembered by those who pur 
sued this course in preference to returning to the head of the chest, that 
the flour from the dustings and returns, before being reduced, was of 
a very superior character, and the writer remembers in his own experi- 



-12 14 ifi 






Flour. 




To Second Dust Mids. 




V 

-12 14 IP 






Flour. 






To Red Dog Buhr 


















GRADUAL REDUCTION MILLING. 


345 


ence that this was a great surprise to him, expecting that the flour would 
be of an inferior character; for, if not so, why was this stock dustings 
and returns? The reason for the superiority of this flour was that the 
stock was sufficiently soft to bolt clean and white, and yet not so soft 
as to paste the reel. It was of inferior quality before being bolted by 
itself, for the reason that in the tiour and dusting reels, which were 
clothed with Nos. 12 and 14 cloth, it had been associated with sharp ma¬ 
terial—middlings, in one instance, and in the other, Hour which con¬ 
tained a large proportion of fine middlings. Being separated therefrom, 
the proportion of sharp material was reduced and it was then possible 
to make clean, bright tiour. This is always the case. 

The great principle in bolting—the controlling principle as to the 
quality of the Hour—is to keep the stock as soft as possible, and have it 
bolt—to continue to reduce the proportion of sharp material as fast as 
the Hour is taken out. It may be done by scalping up to a certain 
point; and then there is the residue of sharp material which is to be re¬ 
duced as another means of making the stock soft and reducing the pro¬ 
portion of sharp material. This was the case in the bolting of the dust¬ 
ings and returns. All having passed through a No. 12 cloth, it was 
not possible to continue the scalping operation farther. After it had 
been floured over a No. 12 cloth it remained to send the tail of the 
reel to the smooth rolls for reduction, after which it was rebolted, and 
again a very good article of clear bakers’ Hour was secured. 

To return to the dust middlings. It was immediately before the in¬ 
troduction of gradual reduction methods that millers of the better class 
determined that No. 12 cloth was too fine for dusting, and that Nos. 8, 
9 or 10 were preferable. This idea secured its development in the grad¬ 
ual reduction milling, and the stock which was neither middlings to be 
purified nor flour—the stock which would pass through a No. 8 or 9 
cloth, and which would not pass through a No. 12, was the dust mid¬ 
dlings. Virtually, it was the product of a No. 9 cloth with the Hour 
taken out, and in roller milling it is a most excellent product. Its qual¬ 
ity is affected largely by the character of the grinding. If the grinding 
be too close, it will be specky and red, and if the grinding be too rapid, 
the stock will not only be specky and red, but flaky and flat as welh 
and difficult of reduction. It is particularly true of winter wheat stock 
that material which has been once reduced more rapidly than desirable 
is influenced for the worse for all future reductions; that, if it has been 


346 


GRADUAL REDUCTION MILLING. 


flattened, it is next to impossible to keep a large proportion of this ma¬ 
terial from running into the low grade stock. 

If the reduction rolls have been set too close at any time, if they have 
been run too fast, or if too much stock has passed to them, it will not 
only affect the break flour and the middlings to be purified, but conspic¬ 
uously the dust middlings. This stock, as said before, should be white, 
granular and bright, and, if properly reduced and bolted, it will make 
flour which rates next to the patent in quality. It is a material which 
cannot be purified by the ordinary sieve and suction machines, but 
which can be purified to a very large extent by the smooth rolls, the 
potency of which as purifiers should never be lost sight of. In this in¬ 
stance their disposition is to reduce the flour particles and, in the case 
of proper handling, leave the impurities intact and in a state to be tailed 
over to the next reduction, or to the low grade stock. The dust mid¬ 
dlings rolls on winter wheat should have about half the grinding capacity 
of the first break. However, in a mill of this size it is not possible, as 
rolls of such a size are not made, for which reason we select the smallest 
size, which is 9x8 smooth rolls; 6x8 or 6x9, or any other size which is 
in the market will do as well. It is a good fault, in this instance, to 
have a little more grinding surface than is absolutely needed, and it is 
ruinous to have less than enough. Where the dust middlings rolls are 
not of sufficient capacity to do their work well the first time, there is a 
loss which is in a degree irreparable. There is a certain amount of ma¬ 
terial which can hardly be saved from the red-dog stock. If one would 
stop to think of it, to think that this material is only in a slight degree 
removed from flour—has passed through a No. 9 cloth—it will be clear 
that it should not take three or four reductions to get this stock down 
to a condition where it may be properly run into the red-dog. Such a 
number of reductions is not at all infrequent for this purpose. If, in¬ 
stead of reducing this stock three or four times before reaching the red- 
dog, the same number of rolls be used to reduce it twice, it will be found 
that by the addition of this grinding surface the stock is thinner, the 
flour therefrom is better, and altogether the various products through 
and over the tails of the reels are better suited to the various classifica¬ 
tions to which they belong. 

In this mill the two reductions of the dust middlings on the 9x8 rolls 
will bring the stock to the red-dog in a condition well suited for such 
material. 


GRADUAL REDUCTION MILLING. 


347 


After this extended generalization on dust middlings, and because of 
the clearness of the diagram, it is hardly necessary to go into a descrip¬ 
tion of the run of the stock, or to account for the various dispositions 
of material which are there indicated. It will be noticed that centrifu¬ 
gal reels are used for caring for this stock. Reels six feet long are 
ample, and their clothing, as here indicated, is justified by what was 
said on this subject during the course of the last chapter. 




CHAPTER LXVI. 


PURIFICATION OF MIDDLINGS ON A 70-BARREL MILL—GRADING OF MID¬ 
DLINGS—SIZING AND SCALPING OF MIDDLINGS. 

The purification of middlings on a small mill is a problem of more 
than ordinary difficulty. When we consider the expense and pains that 
have been brought to bear upon the production of middlings, when we 
consider that their production by corrugated rolls is the sole purpose of 
the gradual reduction of wheat, we can see how illogical, how unreason¬ 
able it is to neglect the middlings—how wrong it is to be careless of that 
which it has cost so much to produce. How often is it that we find the 
six reductions by corrugated rolls elaborately arranged and intelligently 
cared for in respect to these reductions themselves, and, following them, 
how often do we find exhibitions of indifference and carelessness? All 
of this goes to show that the introduction of the gradual reduction 
method into a mill has often been more a matter of impulse than reason 
and intelligence. The system is put in a mill because it has been put in 
other mills. It is used because it is a gradual reduction method. If the 
miller gives the idea, the purpose of his mill serious attention, he will 
realize, aside from the general commercial purpose of making money, 
that it is the making and purification of middlings upon which the suc¬ 
cess of his efforts as a miller and business man depends. 

Now, say that the miller has his six reductions and the following reels, 
or, as in the case of our 70-barrel mill, the five reductions, and the means 
for separating the flour, the middlings and bran as produced by those 
rolls, say he has all this—say he has made the middlings—how utterly 
foolish, how disastrous must it be to his success, if he does not give 
proper consideration to and exercise a proper understanding in the care 
of those middlings. It is the key to his success as a miller. Having 
gone so far as the production of the middlings, there is no retreat, no 
backing down in his care for that grade of stock. It is here that suc¬ 
cess or failure stares him in the face. The value of his flour depends 
on its purity; the purity of the flour depends largely upon the purity of 
the middlings previous to reduction, and the purity of the middlings de- 





GRADUAL REDUCTION MILLING. 


349 


pends upon the arrangement and successful operation of the ordinary 
purification devices. 

In a small mill it is not commercially possible to go into the same 
number of divisions or classifications of stock. It is not possible to 
recognize a large number of differences which would, in a large plant, 
justify classifications for the purpose of distinct and separate treatment; 
but there are certain classifications which must be recognized, no mat¬ 
ter how small the mill may be. If the middlings must be purified, there 
are certain things which must be done in order to accomplish, measur¬ 
ably, the ends of ordinary purification devices. First, there must be a 
grader, and, as to the number of grades, there can be no limitation 
without risk of failure. In fact, there is no reason why the number of 
grades should be curtailed. In this mill, as in the others which have 
been described, is a sieve grader, which, to all intents and purposes, is a 
machine which does the work of several purifiers. This fact is not gen¬ 
erally appreciated. To consider the operation of sieve graders, it may 
be well to take a little space, especially as their use is so important, for 
economical reasons, for small mills. As has been described before, this 
grader is merely a sieve set on hickory springs which are about forty 
inches long. The throw to the sieve may be an inch, and the revolu¬ 
tions of the eccentric shaft 250 per minute. In a small mill of this size 
the sieve should be about twenty inches wide and sixteen feet long. 
There is no need of a conveyor, as the bottom of the sieve is usually 
covered with a light board. 

The middlings are fed upon the sieve at the head, and they travel over 
rapidly in a light, thin stream. The motion of the sieve keeps the lighter 
particles on top. At times there will be more middlings made than at 
others, which means that the sieve will be covered heavier at one time 
than at another, in which event they will not be uniformly graded. 
Small middlings will be carried over beyond their own proper section 
when the stock is too heavy. A remedy for this difficulty would be 
cone pulleys on the driving and driven shaft. The normal speed, in case 
of necessity, might be greater or less than that mentioned. If the sieve 
was not sufficiently covered, there would be impurities which would crowd 
through the cloth. By changing the speed of the sieve according to the 
circumstances, this could be entirely remedied. If the sieve was cov¬ 
ered too lightly, the speed could be relatively diminished. If there is 
too much on the sieve, the speed could be increased. Thus the cover- 


35o 


GRADUAL REDUCTION MILLING. 

ing would become lighter in proportion to the increase. With the grader 
under this control, the middlings would pass over the sieve in the proper 
manner, and the larger proportion of the impurities would float along 
on the top of the sieve. In this mill the grader is clothed as indicated 
below: 

4 2 o oo ooo 

Under each section as here shown is an aspirator. There is a suction 
through the slats which takes out the light impurities and allows the 
middlings to pass through in the proper direction. The middlings which 
pass through the No. 4 cloth and into the aspirator will be in good shape 
for purification, but they will not be visibly affected by the aspirator, 
though it will take out quite a proportion of soft, fuzzy impurities. The 
middlings, after passing through it, wi 1 be in proper shape for the sieve 
purifier. The middlings which pass through the No. 2 cloth and through 
the aspirator will show, in a pronounced manner, the benefits of such an 
action, and the stock removed thereby will be light, thin bran. The 
stock which passes through the No. o cloth will be in most excellent 
condition after having been submitted to the action of the aspirator. A 
sieve purifier of the ordinary type will do this grade of stock very little 
good after having been so treated. As to the Nos. 00 and 000 mid¬ 
dlings, the aspirator will do all for them that can be done previous to 
their gradual reduction by smooth rolls. As seen by the diagram, there 
will be five of these aspirators, as there are five grades of middlings 
which pass through them. Each one of these aspirators is connected 
with the same fan. 

The suction is controlled by the valve, so that there need be no waste. 
There will be a tail over the sieve at the end, which will contain at times 
some coarse stock, more particularly such stock as has passed through 
holes in the scalpers. If arrangements be made for aspirating it, as it 
will contain a large volume of light impurities which float over the tail 
of the sieve, and which may readily be removed, the heavier stock can 
be sent to the third break. 

Herewith is presented a cut showing the arrangement for the purifica¬ 
tion of middlings in our 70-barrel mill. The middlings purification for a 
small mill is a problem of more than ordinary difficulty, on account of the 
limited number of machines which, in the nature of things, must be 
used; and then, again, there are the sizings operations, which invite that 
the same care and skill be displayed, while the size of the plant does 



GRADUAL REDUCTION MILLING. 


35 r 


not permit of a sufficiently large number of operations to do the most 
satisfactory work. The same thing applies to the final reduction of 
middlings. In fact, the general circumstances named are constantly to 
be met in the arrangement of a small mill. 

In this diagram it will be noticed that we have for the purification of 
the middlings, first a grader, 
with the aspirators under each 
section, as before described; 
then four sieve purifiers of the 
ordinary type, two pairs of 
smooth rolls, one reel for each, 
and two reels for the dusting 
of the fine sizing stock; that 
is, the product of the No. 7 
cloth. These smooth rolls and 
reels are as much a part of the 
purification system as the sieve 
purifier, and, according to 
modern ideas, the use of the 
smooth rolls as purifiers in this 
way is as essential to the suc¬ 
cess of the mill as the purifi¬ 
ers proper. 

As to the system, it will be 
remembered that, in the de¬ 
scription of the grader given, 
all of the middlings passed 
through the aspirators. The 
stock drawn out by these as¬ 
pirators is tailings stock, such 
as is shown as going to the 
tailings purifier. The utility 
of this latter machine will be 
considered later. The stock 
from the two first sections of 
the grader, i. e., the material 
which passed through the Nos. 4 and 2 cloths, passes to two series of 
sieve purifiers, that from the No. 4 to one series, and that from the No. 
























































































































35 2 


GRADUAL REDUCTION MILLING. 


2 to another. It will be remembered that the middlings tailed over a 
No. 9 cloth, which fixes the size of the finest middlings, and therefore 
fixes the number of cloth which will be used on the head of the first 
purifier. The number through which these middlings pass while on the 
grader detei mines the number for the body of the machine. The head 
number it will be seen is No. 8, which will allow the finest middlings to 
pass through; then there is the No. 6, representing an intermediate grade 
between the middlings scalping reel and the grader. The No. 4 cloth 
corresponds with the grader cloth. We make a short piece of tail cloth 
of No. 2, which is the number that comes next on the reel. It will be 
seen that no finish is taken off from the first machine, and that the bot¬ 
tom conveyor is arranged to run to the tailings. Thus any portion of 
the stock which passes through the No. 2 cloth may be sent to the tail¬ 
ings. The product of the upper conveyor maybe largely influenced as 
to its appearance by the qualify of the cut-off removed by the bottom 
conveyor. Considering that it is desirable to remove purifier middlings 
from the next machine, and as the middlings which go to this machine 
are cleaner and for that reason will pass through the cloth more freely, 
we use finer cloth on this machine. Thus it will be seen that No. 9 is 
the head number and No. 3 the tail number. The desirable portion of 
the product of the upper conveyor is finished middlings which is sent to 
the middlings rolls. The cut-off from this machine is sent to the next 
coarser grade of middlings. The quality of this cut-off is affected by 
the quality of the cut-off of the upper machine. It will be seen that 
the tail of this second machine is sent to the tailings. 

The next grade of middlings passes through a No. 2 cloth, and the 
clothing of the machine for this grade is influenced, as stated before, by 
the number over which they pass before reaching this grading number 
and by the grading number itself Four is the number used at the head of 
this second series of machines, and it is the number over which the mid¬ 
dlings for this grade pass. No. 2 is the grading number, No. 3 the in¬ 
termediate number, both of which may be noticed on the first purifier 
of this series. There is a small piece of No. 1 cloth on the tail of this 
machine. The cut-off from this first machine is regulated in the same 
manner as previously described for the first machine of the other series. 
The second machine for this grade of middlings is clothed on the same 
principle as described for the other finer grade of stock. The tail and 
cut-off from this machine go to the tailings. The middlings which pass 


GRADUAL REDUCTION MILLING. 


353 


through the Nos. o, oo and ooo on the sieve grader do not pass to the 
sieve purifiers of the ordinary type. Where the aspirators of the pattern 
described are used, the middlings which pass through them will be in 
most excellent condition. All of the fine stock, bran, etc., will have 
been removed. 

We will consider the sizing of the middlings of the No. ooo grade 
first. They should pass through a pair of 9x12 rolls, and from thence 
into a reel clothed with Nos. 7, 2 and o, as shown. The product of the 
No. 7 is indicated as going into the two reels below. The tail of the 
No. o goes to the tailings. The quality of these tailings will be regu¬ 
lated by the adjustment of the rolls. If the rolls be set too close, the 
tailings will be fiat and rich; if they are too open, the stock will neces¬ 
sarily tail over in an unreduced condition. The product of the No. 2 
•cloth and the No. o pass to the second sizing rolls. The No. ooo mid¬ 
dlings have been reduced to a size to correspond with the next finer 
grade, particularly that coming through the No. o cloth. This stock, 
together with that which comes through the Nos. o and 00, passes to the 
second sizing rolls, and from the rolls to the reels immediately below. 
The product of the No. 7 cloth goes into the two reels before described. 
The product of the No. 4 cloth of that reel, i. e., the second sizing reel, 
goes in with the No. 4 middlings of a corresponding grade, which are 
taken through the head of the middlings grader; or, to be more specific, 
they go to the first two purifiers which purify that grade of middlings. 
Then the middlings which pass through the No. 2 cloth of the second 
sizing reels go to the purifiers which take the corresponding grade of 
middlings from the grader. The tail of the No. 2 cloth is tailings. 

Now, as to this sizings operation. It will be noticed that the mid¬ 
dlings of the Nos. o and 00 grades are reduced gradually to grades cor¬ 
responding to that of the middlings which come through the first two 
sections of the grader, but which middlings from the sizings do not pass 
to the grader, but rather directly to the purifiers of the two respective 
grades; that is, Nos. 4 and 2. Thus we have the middlings which orig¬ 
inally pass through these numbers as being purified and sent to the mid¬ 
dlings rolls, and the large middlings reduced and purified with and as a 
part of the same stock, the entire body of which passes to the middlings 
rolls to be purified. 


CHAPTER LXVII. 


CONTINUATION OF MIDDLINGS PURIFICATION FOR A 70-HARREL MILL- 

SIZING OF PURIFIED STOCK—FINAL REDUCTION OF MIDDLINGS BY ROLLS 
A SIZING PROCESS—SEPARATION OF REDUCED MIDDLINGS. 

The first two and the finest of our five grades of middlings were 
graded through Nos. 4 and 2 cloth, and the last three and coarsest 
grades through Nos. o, 00 and ooo. The only purification which these 
latter grades received was the action of the grader and the aspirator 
which was placed under them. After this process of grading and aspi¬ 
rating these coarse middlings, they were submitted to the sizing rolls, 
which name is a misnomer, as they are nothing more nor less than 
smooth, gradual reduction rolls. They gradually reduce the coarse ta 
fine middlings. Sizing, as it was originally understood, took a conglom¬ 
erate quality of middlings and brought the larger to a size conforming 
to the smaller. However, this expression—that is, the sizing—carries 
its own meaning as applied to the present processes, and there is no 
serious reason for making a change. At all events, the three coarser 
grades of middlings which were taken from the grader were reduced to 
conform in size to the first two and finest grades of middlings; that is r 
the Nos. o, 00 and ooo middlings were gradually reduced by the smooth 
rolls to Nos. 4 and 2 middlings, after which they were purified with the 
middlings of that grade. 

In this arrangement the writer has endeavored to carry out what he 
regards as the true system of purification in a very small mill. After 
the middlings have passed through this process—after they have been 
treated on the sieve purifiers—we run them to a pair of smooth rolls. 
The coarsest middlings which we have there, are those which pass through 
a No. 3 cloth. The pair of rolls which reduce these middlings are noth¬ 
ing more nor less than sizing rolls, or another step in the way of gradual 
reduction rolls. 

Before going on with the separation of this reduced stock, we will call 
attention to another grade of stock which was not treated or considered 
in the preceding chapter; that is, the material which passed through the 


GRADUAL REDUCTION MILLING. 


355 


No. 7 cloth from the first and second sizing rolls reels, the product of 
which is always nice, fine middlings and a high grade of flour. This 
stock we run into the reel as indicated by the diagram, together with 
the stock of reduced middlings—the middlings of the Nos. 4 and 2 
grade. r l hus we have this reduced middlings stock and the product of 
the No. 7 cloth on the sizing rolls reel as running to the same reels for 
the purpose of separating the flour and middlings. This arrangement 
saves complication ami accomplishes good results in a very direct way. 

The product of the middlings rolls and the two sizing rolls reel passes 
first to a red clothed with Nos. 12, 14 and 4 cloth. The product of the 
No. 12 and a part of the No. 14 cloth is flour. The cut-off from the 
No. 14 and the product of the No. 4 goes to the next reel below. 
The tail from the No. 4 cloth is tailings. The middlings rolls will pro¬ 
duce quite a little stock which will tail over this reel, and properly so. 
The stock which passes to these reels should not be squeezed or mashed 
in a way to flatten into hard, wafer-like shapes, but should be treated 
the same as if it were being sized or broken. A well known foreign 
writer on milling topics has said that excessive pressure on rolls has a 
tendency to solidify rather than to separate or disintegrate the stock, 
which fact is a good thing to bear constantly in mind while setting smooth 
rolls. 

If middlings could be made absolutely pure, only the final reduc¬ 
tion machinery, without the following separating reels, would be neces¬ 
sary in the disposal of that grade of stock. Properly speaking, the 
final reductions of the middlings represent the last efforts in the direc¬ 
tion of purification before the stock is put into barrels. It should be 
understood as such, and the handling of that machinery should be on 
the basis of such an idea. This view of the question of the final re¬ 
duction of middlings settles the problem in the writer’s mind as to the 
proper machinery for such a purpose. 

The reduction of middlings is naturally and properly a gradual reduc¬ 
tion, and is in a line with the continuation of the previous process of 
sizing. With a complete system of middlings purification it would be 
difficult to tell where the one began and the other left oft'. All would be 
a continued process of sizing and a constant taking off of flour and con¬ 
sequent purifications, until all the stock would be worked into flour 
of one grade or another. Under any circumstances there can not be, or 
should not be, a mashing or squeezing by the rolls, any more than there 


356 


GRADUAL REDUCTION MILLING. 

should be with the millstones. The flaking and softening of the stock is- 
no more desirable in one instance than is rasping, pulverizing and tear¬ 
ing in the other. Reduction by smooth rolls can not be properly grind¬ 
ing or mashing. It is a sizing process which takes the stock and re¬ 
duces it to dimensions indicated by the appreciable difference of space, 
which should separate the rolls when doing their work. A good reduc¬ 
tion is always contingent upon the possibility of purification, and is met 
by the conditions above indicated. The time will come when the line 
between the purification and reduction of middlings will be less clearly 
marked. It will be at a time when the full idea of the broad principles- 
of gradual reduction are recognized and appreciated in detail. 

Now if the middlings rolls be set carefully, not too closely, the stock 
which tails over the No. 4 cloth on the reels in question will be just the 
kind of stock which belongs to tailings of a poor quality, and the stock 
which goes to the next reel will bolt nicely. The product of the No. 7 
cloth, which, by the way, might be No. 6 on soft wheat, will be second 
middlings of a most excellent quality. The effect of this whole opera¬ 
tion on the purification of middlings, and in which process of purifica¬ 
tion the writer wishes to be always understood as including the smooth 
rolls and the reels which follow, has been to reduce the whole volume of 
middlings which originally pass through the grader, which were of a size 
from No. 4 to 000, to a grade which would pass through No. 7 cloth. 
Thus we have as passing to the second middlings buhr, as we call it, a 
grade of clean fine middlings which have been dusted over a No. 14 
cloth and which will pass through a No. 7. These middlings will be fine 
and clean and bright. This system will be carrying out the idea of the 
gradual reduction and purification of middlings in a way that can not 
but be satisfactory from a milling and commercial standpoint. The mid¬ 
dlings are of a size which can be readily and conveniently reduced on 
buhrs, which method is adopted in this mill. 

The middlings, after having been ground in this way, pass to the reel 
shown on the diagram clothed with Nos. 12, 14 and 9 cloth. The pro¬ 
duct of the 12 and 14, for the most part, is patent flour. The cut-off 
from the No. 14 and the desirable portion of the No. 9 go to the reel 
below clothed with Nos. 12 and 14 cloth. The tail of the No. 9 will 
properly belong to the tailings, as will a certain proportion of the pro¬ 
duct of that cloth. It will be noticed that the conveyor under it is so 
arranged that any portion of it may be sent to the tailings. Thus the 


GRADUAL REDUCTION MILLING. 


351 


quality of the stock which goes into the reel below is subject to the 
control of the miller. This is a very important arrangement, and one 
which should not be neglected. If a miller will take occasion to exam¬ 
ine the product of the tail slides, he will often find red, foxy stock 
which should not go into the flour reel when it is possible to run it in 
another direction. This is just what is done in this instance. All or 
any part of the product of the No. 9 may go to the tailings. 

Attention is called, as has been done many times before, to the cloth¬ 
ing of the bottom reel as here shown and the reasons which lead thereto. 
Reels are ordinarily so clothed; that is, there may be Nos. 12 and 14 
cloth on the upper reel and Nos. 12 and 14 cloth on the lower. A 
supetficial method of reasoning might say that after having cut off flour 
or stock which passed through the No. 14 cloth, why is it to be sup¬ 
posed that flour of a good quality may be taken from a No. 12 cloth on 
a reel immediately under it, as according to the arrangement here shown?' 
If No. 14 cloth was on the tail of the first reel, such reasoning would be 
correct in the conclusion that the product of the No. 12 cloth would be 
inferior to the product of the No. 14 cloth above. It is the scalping 
cloth on the tail of the first reel which affects the quality of a material 
in a way to produce flour of a high grade—flour of a quality superior to 
that which passed through the No. 14 cloth on the reel immediately 
above. The No. 9 cloth not only removes bran particles and red stock, 
but it reduces the proportion of sharp stock which would prevent 
proper bolting through any flour cloth. It is entirely possible to ini- 

t 

prove or to in other ways affect the product of flour on the lower reel, 
by regulating the softness of the stock which passes into that reel by the 
slides of the upper conveyor under the No. 9 cloth of the upper reel. 
The more stock that is run to the tailings from the tail of this upper 
conveyor, the softer will be the stock which goes into the lower reel, 
and, for that reason, the flour will be very much improved. The cut-off 
and tail of the lower reel go to the dust middlings. This stock might 
be called third middlings. 


CHAPTER LXVIII. 


TAILINGS OF THE SEVENTY-BARREL MILL-UNCERTAINTY OF THE VOL¬ 

UME OF TAILINGS—COMPOSITION OF TAILINGS—END OF PURIFICATION 

METHOD-REDUCTION OF TAILINGS BY SMOOTH ROLLS-CHANGE IN 

DIFFERENTIAL MOTION FOR REDUCTION BY SMOOTH ROLLS-LIMIT OF 

POSSIBILITIES OF REDUCTION BY SMOOTH ROLLS. 

We have said before that tailings was an uncertain product—might 
mean different things in different mills, might be rich in one and clean 
in another, and still be called tailings. As a matter of fact there should 
be, in mills of a size to justify it, a product which is intermediate be¬ 
tween purified middlings and tailings. There are a few mills arranged 
on this basis, but it is not a common practice. Tailings necessarily con¬ 
tain some very low stock—oftentimes the larger portion of it might go 
to the feed. But mixed with and a part of it are bits of middlings and 
flattened stock, stock which contains very good Hour. If the tailings be 
very poor, if the various products which go to make it up be uniformly 
thin and light, there cannot but be certain material from which this ma¬ 
terial was taken which is below the proper standard. Say, for instance, 
that the stock which comes from the middlings purifiers is very poor, 
thin and red. This condition would naturally imply that the middlings 
were not as well purified as they might be. In the case of the mid¬ 
dlings, there is a certain amount of material which would hardly be re¬ 
garded as middlings which were sufficiently well purified to go to the 
purified middlings bin, and the miller can not, with an easy conscience, 
send it in with the low stock which goes to the tailings, hence an inter¬ 
mediate product, as suggested above. 

The volume of tailings, the proportion of such stock as compared 
with the other material of the mill, is affected largely by the care and 
skill exercised in the treatment of the sizing rolls, and in the arrange¬ 
ment and the clothing of the reels which follow. If the rolls be run too 
slow, there will be a certain amount of fiat stock which will run over to 
the tailings. If such rolls be run too much open, there will also be ma¬ 
terial running in this direction. Waste, under this latter condition, is 





GRADUAL REDUCTION MILLING. 


359 ' 


less liable to occur than under the former. The miller is more liable to 
notice waste when the rolls are open than when they are too close. In 
one instance he will notice the middlings tailing over; in the other he 
will see the flat stock and the bran tailing over together. The middlings 
show for themselves; the flat stock may be mixed with the bran, for 
which reason it will not be readily perceptible. The clothing of the tail 
of the scalper from the sizing reel is important in affecting the volume 
of tailings, in that it may be too fine, and the miller, in his efforts to get 
the most of the middlings through the cloth, will crush too close and 
thus waste largely. Soft wheat will make a larger proportion of tailings 
than hard wheat. From the soft wheat the middlings are apt to be flat¬ 
tened in reduction. Where this occurs, the tailings rolls are sure to be 
surfeited. 

A tailings purifier has been spoken of and indicated. A purifier has 
a place wherever impurities can be taken out in such quantities as to 
justify in a commercial sense their application to any grade of stock. As 
said before, the tailings are usually a conglomerate mass. They contain 
very poor stock, some of which belongs to the feed, and, at the same 
time, very fair stock, for which reason it is entirely justifiable to attempt 
to make a separation of the very poor and thoroughly good material. 
A purifier belongs as much to the clear flour, or to the low grade, for 
that matter, as to any other part of the mill. It is usually associated 
solely with the patent flour. As the purity of flour affects its value, it 
is well to make the effort to purify, as far as possible, all grades of stock. 

The tailings of this mill are made up largely of the products of the 
aspirators which are placed under the graders. The richest stock which 
is to be found going into the tailings will be from the bottom conveyor 
of the last purifier, which operates on No. 2 middlings. The stock go¬ 
ing to the tailings from the second sizing will be richer than that from 
the first. The stock from the reel which dusts the No. 7 sizings mid¬ 
dlings and the stock from the middlings rolls will be a little flat and 
somewhat whiter than the other material. It need not be rich, however 
—will not be except in the case of very close grinding by the middlings 
rolls. The tailings from the second middlings buhr will be fine and red. 
The tailings purifier, as shown, is a sieve separated into four divisions, 
with an aspirator under each. It is graded 4, 2, o, 00. The suction may 
be adjusted to suit each grade of stock, and in that way there need be 
no waste. The tail of the 00, coming, as it does, over a sieve, will be 
(23) 


360 GRADUAL REDUCTION MILLING. 

very light stock, and in this instance there will be quite a volume of it. 
This statement is also true of the material which passes through the o 
and 00. The suction may operate quite actively on this material. An 
aspirator will do very little good on the No. 4 stock, though it will take 
out a certain amount of material. It will be white and hat, and if 
means were convenient it would possibly be well to send this material 
to the red-dog; if not, the suction should be extremely light. In any 
event, stock which passes through No. 4 cloth on this tailings purifier 
will not be a poor grade of material. This effort at the purification of 
the tailings is a very great benefit to that grade of stock. Not only is 
the quality of the Hour improved by so doing, but the quality of the 
stock is of such a character that it may be more readily reduced by the 
smooth rolls than could be the case under other circumstances. The 
fine bran and soft stock which is taken out by the separator has a tend¬ 
ency to make a smooth roll reduction anything but complete and satis¬ 
factory. Not only is the volume of stock large, but it is of a spongy 
nature, which makes it difficult and unsatisfactory to handle. Another 
thing which the purification of these tailings would do would be to sug¬ 
gest further purification. The miller would look at it, see the change 
that is made, and it would immediately occur to his mind that other 
operations would be in order. 

With this grade of stock, however, there is a point beyond which puri¬ 
fication by ordinary means ceases to be effective. The purification by 
smooth rolls is, after a certain stage has been reached, the only effective 
and conclusive method. It was the habit, during the days of new pro¬ 
cess milling, to take tails from the purifiers, repurify them, and send the 
product back to the other purifiers. But then the sizing operations were 
not carried on to the same extent as now, and the large proportion of 
fine bran was not separated from the Hour, as is now the case. The 
tailings from sizings rolls can not be purified beyond a certain point. 
One or two operations by a purifier will do about all that can be done 
for them, except, as said before, what may be done by the smooth rolls. 
A great mistake is made in the reduction of tailings by smooth rolls in 
setting the rolls too close, in mashing them too much. In this event 
there is a large proportion of flattened material which goes either into 
the feed or into the red-dog. If the rolls be carefully adjusted, the 
middlings will be broken and only a small proportion of the stock flat- 


GRADUAL REDUCTION MILLING. 361 

tened. Consequently only a small proportion of flour stock will go in 
other than the proper directions. 

The tailings in this mill are reduced by smooth rolls, and, as shown, 
the separation is made by a centrifugal reel. The writer does not think 
that a centrifugal reel is the best reel to use in the separation of tailings 
stock. It is used here as an economical means of producing flour, not 
so much in the cost of the plant as in cost of the flour. Quite a differ¬ 
ence may be made in the product of the tailings rolls by a change in the 
differential motion of such rolls. While the differential \£ excessive the 
flour will be more ragged; it will feel longer, will contain a larger pro¬ 
portion of deleterious material than when the reductions of such stock 
are made with a smaller proportion of differential. The action of the 
differential motion of smooth rolls is to elongate the stock. This quality 
or tendency is limited by the liability of the stock to break If a piece 
of dough were passed through the smooth rolls it would be flattened out, 
or elongated. The amount or proportion of elongation would be esti¬ 
mated by the differential motion of such rolls. The tendency of one 
roll to hold back and of the other to advance may be estimated by the 
excess in speed of one roll over another, and the elongating qualities on 
such a movement are exactly in proportion as the difference in speed. 
It is evident that the breaking action will predominate; that is, that 
there will be more breaking than elongation in flour stock. There can 
not be much elongation of middlings or brittle material of that kind. 
It will be broken. There is a limit to the elongating qualities of all ma¬ 
terial which goes on rolls, whether it be impurities or otherwise. Where 
the differential is excessive, it is apparent that a certain large proportion 
of the impurities would be broken and pulverized by the differential ac¬ 
tion of the rolls. As an illustration of possibilities, we will say that the 
motion of the rolls be integral; that is, that there be no difference in 
speed. There will be a compressing of the stock, and certain portions 
of it will be broken; there will be very little of the pulverizing action, 
either of legitimate flour or of impurities. The flour stock will be inci¬ 
dentally pulverized and broken, and the impurities, which are usually of 
a tougher character than the better material, will not be appreciably dis¬ 
turbed. 

It is the tendency of all millers to want to pulverize or to make flour 
on most reductions, and especially the tailings and the lower grade rolls 
of this kind, and for this reason it may be expected that there will be a 


3 62 


GRADUAL REDUCTION MILLING. 


certain amount of differential at all times for the reduction of this ma¬ 
terial. In fact it can hardly be expected, nor is it desk able that there 

be differential motion wherever smooth rolls are used. The disintegra- 

% 

ting action of this movement is so gentle when the rolls are not set 
closely together that it can not but be desirable, though the amount of 
such differential may be varied according to the quality of material to 
be handled. With belt rolls it is a very simple matter to vary the move¬ 
ment, and it will be easy for any miller to demonstrate to his own satis¬ 
faction the proper motion to select in the reduction of tailings. There 
is a disposition among many who handle these rolls to set them very 
close, which is entirely wrong, principally because it does not accom¬ 
plish the desired end. There is a lurking idea in the minds of many 
millers that the closer the rolls are set—the closer it is possible to set 
them and still keep the belt from slipping, the greater will be the amount 
of work done by such rolls. That is wrong. 

There is a proper point in the setting of rolls, one which will accom¬ 
plish more work than any other, and it is not the point where the great¬ 
est amount of power is consumed or where the rolls are set the tightest. 
It is where the stock is broken and not flattened. This is the greatest 
evil, the place where the greatest wrong is done to the stock in milling 
—this same close setting of the smooth rolls. It is a very simple mat¬ 
ter to judge when rolls are doing their proper work. The stock, as it 
comes from them, feels as though it had been ground and not mashed. 
Not only will the amount of flour made by the proper setting of the 
rolls be greater, and not only will the proportion of pulverized impuri¬ 
ties be less, but the amount of power used will be greatly less. A miller 
says to himself: “I have only a few pairs of smooth rolls. I have not 
enough. Therefore I must set these rolls very tight that I may hasten 
the operation of reduction.” He does not do anything of the kind. 
He cakes and hardens the stock. He makes it impossible to reduce 
this stock on anything short of a millstone. The stock having been thus 
treated on one set of rolls, those following have very little effect in has¬ 
tening the work of reduction. 

The writer once heard a verv forcible illustration of the reducing 
power of smooth rolls. It was by a Hungarian miller. He had been 
working in a mill where there were two pairs of smooth rolls, some three 
or four reels four or five purifiers with adjustable sieves, and one or two- 
pairs of millstones. All the work of the mill was done on this ma- 



GRADUAL REDUCTION MILLING. 


3 6 3 


chinery. One or two reductions at a time were made on the rolls that 
were in the mill, they being adjusted for each class of material to be 
handled, while the middlings and bran were reduced in their proper or¬ 
der on the millstones. It was the habit of the head miller of this mill 
to reduce all of his middlings on stones, and the miller who related this 
said to him at one time: “Why do you not reduce your middlings on 
these smooth rolls?” Said he: “We do reduce them as far as we can. 
We reduce them to dunst middlings (fine middlings) on the smooth 
rolls, but we can not reduce them farther by such means.” The miller 
said: “It is my watch to-night, and if I may, I will try;” and with the 
consent of his superior, he did try. There was an accumulation of 
some ten barrels of this stock which had been produced by the breaking 
down of the larger middlings. He commenced to run it through the 
rolls, having it carried there by the help, and from the rolls to the reels. 
He reduced very carefully and very gently, and got very nice flour. He 
had the middlings carried back to the rolls and passed through them 
again with the same result—very nice flour. The third and fourth time 
was this repeated. Then he had about four barrels of stock remaining. 
After this the smooth rolls were almost inoperative. The stock kept 
going around and around without producing Hour. He had been very 
careful; he had reduced the material very gently, only a little at a time, 
yet after four or five reductions on middlings which had passed through 
a No. 6 cloth, say, very little flour could be made. 

To the writer this illustration meant a great deal. It showed or rather 
confirmed his belief that a complete corrugated and smooth roller mill 
is not quite the thing. It is hardly possible to completely reduce the 
product of the corrugated rolls with the smooth rolls. These rolls will 
go only so far, however carefully they may be handled, and no farther. 
There will be a certain amount of stock of most excellent character 
which is tailing over to the red-dog, and if the red-dog rolls be smooth 
iron, they will be tailing over the feed. In the case referred to, the 
miller said that after he had reduced the stock five or six times or more 
and found that little or nothing was being done on the last two or three 
reductions, he had it carried to the millstones and there reduced. As 
the material had been scalped repeatedly during the process of this re¬ 
duction by smooth rolls, it was well purified and was for this reason in 
good condition to be handled by the millstones. It made most excel¬ 
lent Hour, of a very high grade. After all, the use of the smooth rolls 




364 GRADUAL REDUCTION MILLING. 

in this way was not without its beneficial results. Smooth rolls, properly 
used, are always purifiers. In behalf of the millstone idea for the pur¬ 
pose of reducing certain grades of stock in a roller mill, we may call to 
mind the fact that more millstones are used by Hungarian millers in pro¬ 
portion to the amount of flour made, than by the best American millers. 
Millstones are more necessary in aiding in the 1 educing of soft than of 
hard wheat. 


CHAPTER LXIX. 


COMPLETION OF SEVENTY-BARREL MILL DIAGRAM-LIST OF MACHINERY 

USED-GENERAL VIEW OF SEVENTY-BARREL MILL DIAGRAM. 

The completed diagram of the 70-barrel mill is here given. By look 
ing at it, it will be seen that we have the following machinery, aside from 
that used in cleaning the wheat: Five pairs of corrugated rolls, six pairs 
of smooth rolls, two pairs of millstones, five scalpers, three short reels, 
five 14-foot reels, five centrifugals, one grader, four small purifiers, and 
one aspirating purifier. This may be slightly more than the machinery 
ordinarily used in a 70-barrel mill. This is intended to be a mill which 
will make money when competing with others in the general market. It 
is not a frontier arrangement, or a mill which has a local trade to depend 
upon, without competition from larger mills. In sections where there 
are no roller mills, a cheap mill, an incomplete mill, will pay about as 
well as anything. In many places a stone mill will do the work of 
making money. In sections of the country where a mill has a local 
trade which is not interfered with by other mills, it is not necessary that 
the most complete and elaborate diagram be followed. But for a 
mill which is intended to enter into the general market, for one which 
must compete in the east and elsewhere with the larger and more com¬ 
plete mills, it is necessary that particular attention be paid to the cost 
and quality of the product. There is only one weak point, that is, ma¬ 
terially weak, in this mill, and that is in the use of only five reductions. 
Six would put it on a better footing. 

The separation and reduction of the dust middlings and other soft 
stock, including the break flour, is in a very good condition, and will 
bring about good results. The purification of the middlings is cared for 
with some conside:able pains. It is recognized that in a mill never so 
small it is always important that the product of middlings be purified; 
that in any gradual reduction mill, middlings making and middlings puri¬ 
fication is the general purpose, and if one neglects to purify the mid¬ 
dlings, it is clear that he might just as well have neglected to make 
them. After going to the expense and pains of making middlings, they 


^66 GRADUAL REDUCTION MILLING. 

should be well purified, otherwise it is not necessary to go to that pains 
and expense. The same thing is true of the reduction of the middlings. 
The tailings are cared for more elaborately than is common, but the 



tion of the stock, thus materially benefiting the quality of the break flour. 












































































































































































































































GRADUAL REDUCTION MILLING. 


367 


Fo take a general view of the details of the diagram, these things may 
be noticed: In the first place, three separations are made on the first 
break scalper—first the low grade flour and low grade stock through the 
head of the reel from the body of the stock; next the middlings from 
the tail stock, which includes the separation of the tail from that which 
has gone through the reel. These make the three separations. We 
next separate the low grade flour from the low grade stock which is to 
be reduced, then we take the product of the second, third and fourth 
breaks, and separate the flour and dust middlings stock from the mid¬ 
dlings which go to the grader. Next we separate the flour from the dust 
middlings. The tail of the scalper of the four middle breaks goes to the 
middlings grader, where the middlings are graded into five different 
grades, the 4 and 2 grades going to separate purifiers, and the o and 00 
grades going to one set of smooth rolls and the 000 grade to another. 
The 000, the 00 and the o grades are reduced gradually until the mid¬ 
dlings correspond to the 4 and 2 grades, this reduction being accom¬ 
plished by the means of smooth iron rolls. After they have been thus 
reduced they are purified with the middlings of that grade, all of which 
•stock runs to another set of middlings reduction rolls, which brings the 
entire product down to a fine grade of very pure middlings, which may 
be reduced on a millstone and produce most excellent flouiv All grades 
of these middlings have been purified so carefully that the flour made 
from the various reductions is suitable for patent flour stock. The larger 
bulk of the patent flour will come from the middlings reduction stone, 
which is intended to make the larger volume of the patent flour. The 
middlings which are taken from the reels which handle this millstone 
stock are sent to the dust middlings. After having been reduced by the 
millstones, this stock is again in a condition to be well handled by rolls, 
and it is submitted to two reductions by the smooth rolls. Any part of 
the stock which will not go through the flour cloth is sent to the tailings, 
where it receives an additional reduction. The stock from the dust 
middlings reductions is separated on centrifugal reels, as is also the 
stock from the tailings rolls. The tail of the second dust middlings and 
that from the tailings rolls reel, together with various other stocks of low 
grade character, run into the red-dog bin, which stock is again in a con¬ 
dition to be reduced by the millstones. It is hardly possible to reduce 
the red-dog product of smooth iron rolls on smooth iron rolls. It is the 
next thing to impossible, and as a natural consequence a millstone is 



3 68 


GRADUAL REDUCTION MILLING. 


used for this purpose—not but that the smooth rolls would make better 
tiour, what there was of it, but it would be small in quantity unless agi¬ 
tators or other mixing machines were used. At another time it was de¬ 
scribed how this stock might be reduced on smooth iron rolls by the use 
of agitators. While the millstone tiour from the red-dog is not of so- 
high a quality as that from rolls, it is much larger in quantity, which wilt 
more than compensate for the difference. 


A FIFTY BARREL MILL 












CHAPTER LXX. 


A 5©-BARREL MILL—MACHINERY FOR 50-BARREL MILL-WHEAT CLEANING 

-CAPACITY OF WHEAT CLEANERS—MAGNETS—INFLUENCE OF WHEAT 

CLEANING ON YIELDS—SCOURING MACHINES. 

A 50-barrel mill is about as small as a gradual reduction mill can be 
made. At the same time, with the machinery now at hand, such as is 
now made at various manufactories, it is entirely possible to make such 
a mill and properly proportion it for reduction machinery. The roll^ 
must necessarily be shorter, the scalpers and reels shorter, and the puri¬ 
fiers smaller. It is not long bince the smallest rolls made were 9x18 
inches, and he who desired to build a smaller mill than one in which a 
9x18 roll would naturally take a division of stock, was forced to so di¬ 
vide his stock as to have enough for that roll to do, and, in the same 
measure, reduce the number of his reductions. At such a time, three 
and four break mills were more common than they are now, and many 
grades of stock had to be run together which would better have been 
separated. Now we can get a pair of rolls, smooth or corrugated, from 
7 to 30 inches in length. Their small size renders it possible to make 
the smaller classifications on a small mill and carry out the true princi¬ 
ples and ideas of gradual reduction. In making a mill as small as the 
one here under consideration, it will not be attempted to make a dia¬ 
gram which is as elaborate as to separations and classifications of stock 
as upon a larger plant. While it is mechanically possible, the scheme is 
not regarded as commercially feasible. A diagram will be given of a 
mill which will make most beautiful Hour and make it cheaply. The 
matter of yield will not be lost sight of any more in a small mill than in 
a large one. 

As to the cleaning machinery: In the first place we will make provi¬ 
sion for taking out a certain amount of dust from the head of the first 
wheat elevator, whence the wheat will run to a rolling screen clothed 
with square wire—wire with square edges rather than round surfaces. 
The reel should be about 12 feet long, for the purpose of getting the 
full benefit of the scouring action. The same fan which connects with 


372 


GRADUAL REDUCTION MILLING. 


this rolling screen might also connect with the head of the wheat eleva¬ 
tor for the purpose of carrying out dust. Three-fourths of the reel 
might be clothed with No. 12 wire, which would take out a certain pro¬ 
portion of the screenings and other light, fine stock, and the other one- 
fourth of the reel would be clothed with No. 6 wire, through which the 
wheat would pass, and over the tail of which would go the grains of corn 
and bits of straw and other coarser impurities. In the natural course of 
things the cleaning machinery for this mill would have to take care of 
about nine or ten bushels an hour, but as in such mills it is not always 
desirable or possible to run the cleaning machinery all the time, it would 
be well to select sizes of separators and scouring machinery which would 
clean, say, twice that much stock. 

' It may be noticed by an examination of the catalogues of the makers 
of various wheat cleaning machines that the second size which they 
make is the one adapted for this capacity; that is, twenty to thirty bush¬ 
els an hour. The smallest size is intended to take care of ten to fifteen- 
bushels an hour. Now while it is true that most mills work their clean¬ 
ing machinery in excess of its maximum capacity, it is also true that they 
will do better work when operated to their minimum capacity only, and 
in this mill this would be advised. In some sections of the country it 
is necessary to use cockle machines. In such instances a combined 
cockle machine and separator may be used to follow the rolling screen. 
It might be well to mention, however, that where the rolling screen is 
used it would be well to place the magnets of the ordinary horse-shoe 
pattern in the tail spouts of this reel, or in case of the separators only 
being used, the magnets should be placed in the spout which leads from 
the separator. The machine which collects the metallic deposit auto¬ 
matically is more effective and convenient, though more expensive, than 

4 

the horse-shoe magnet. However, the cost is not great. A miller can 
well afford to be quite lavish in the use of magnets. The writer remem¬ 
bers to have heard the president of the Millers’ National Association, in 
one of its meetings at Chicago, say that he had used the magnet in con¬ 
nection with bran as well as in various other parts of the mill, and in 
every instance they made collections of foreign metallic substances. 
While this illustration was an extreme one, it merely shows the general 
effectiveness of the separation. The saving in bolting cloth by their 
use is very great. 

After the wheat leaves the separators it should be run to the scouring 


GRADUAL REDUCTION MILLING. 


373 


machine, if a cockle machine be not used. In a mill of this size it is 
hardly to be expected that more than one smutter or scouring machine 
will be used, though two would do the work better and more economic¬ 
ally. But considering that we have the benefit of the scouring action 
of the rolling screen with the square wire, we will not include more than 
one other scouring device, in which event we would use one which will 
handle the wheat with the greatest severity, yet without the possibility 
of injuring the external bran coating. 

After the wheat leaves the smutter it is elevated to the first reduction 
stock bin, or in case the larger size machines be used, as suggested, it 
would be of advantage to pass the wheat through the cleaning machin¬ 
ery a second time, if the means are at hand to do it, or if it can be con¬ 
veniently arranged so to do. This would merely include the use of an 
■extra bin. The greatest benefit which the wheat would derive from the 
repetition of this process would be that the wheat cleaning and scour¬ 
ing might be more gradual, and for that reason more economical and 
more efficient. Not only would it be more economical as to yield, but, 
as has been stated before, it would reduce the proportion of low grade, 
in that there would be less stock cut of which to make low grade Hour 
—less low grade stock in the mill. Much has been said before on this 
subject of wheat cleaning, but the writer is encouraged to keep on say¬ 
ing, for he believes that the next advance which is made in a general 
way by the millers throughout the country will be through the medium 
of wheat cleaning methods. 

In a conversation with a miller, it was remarked that he cleaned his 
wheat very well, very thoroughly, and for that reason his screenings were 
rather rich. It has been practically demonstrated to the writer that the 
fact that the screenings were rich does not indicate that all of the 
screenings have been taken out of the wheat, or that the wheat has been 
well cleaned. It is entirely possible to have very rich screenings— 
screenings with quite a proportion of wheat in them, and at the same 
time to have wheat which is imperfectly cared for. The successful 
cleaning of wheat, successful as to the ultimate result and successful in 
that it is done economically, can be accomplished best by gradual 
methods. We discovered first that we could get the most middlings by 
gradually reducing the wheat. Afterward we discovered that middlings 
could be best purified by a gradual process. It remains to be developed 
in the minds of a majority of millers that the wheat can be best and 


374 


GRADUAL REDUCTION MILLING. 

most economically cleaned in a gradual manner. There are those who 
acknowledge that the wheat can be best cleaned in this way, but who 
would not be so ready to acknowledge that it could be done the most 
economically in this way. As a matter of fact, of recent development,, 
the yield of flour from the wheat can be appreciably lowered by the 
multiplication of the wheat cleaning machinery. Not only will the 
quantity be greater, but the proportion or yield of high grades will be 
much larger than when less gradual methods are adopted. 

The man who tried the experiment of adding to his wheat cleaning 
plant for the purpose of more perfectly cleaning the wheat, discovered 
the facts as here represented, that he took less stock out of the wheat,, 
a smaller proportion per bushel with the gnder, than he did with a lesser 
number of machines. The reason for this may be understood when we 
remember that in the ordinary effort at wheat cleaning, where we have 
to do the best that can be done at one or two operations by the sepa¬ 
rator, the suction has to be stronger for the purpose of making a sepa¬ 
ration, stronger than it might be if the feed were lighter and if other 
operations were to follow. It is clear that the gradual removal of impu¬ 
rities from the wheat is more efficient and more economical, and in 
every way more satisfactory, than when less gradual methods are in use. 

If we stop to think of the methods of middlings purification as com¬ 
pared with the methods of wheat cleaning purification, we can notice 
the analogy—understand and appreciate the necessity for a similarity of 
means. We know that one or two operations will not do much good 
on a large volume of ungraded middlings, but we are not so well aware 
that operations founded on the same idea, which include two or three 
handlings of this grade of stock, are in very common use, and without 
apology or without acknowledgment that it is not right. A miller who 
purifies his middlings on such a plan would have it in mind to add to 
his facilities as soon as opportunity offered, as soon as he had money, 
or as soon as some other thing happened to enable him to make the 
change. Still he will go on in the same old way, year after year, in the 
cleaning of his wheat, without thinking that there is a better way. 
There are not many millers who would think to reduce their yield five 
or six or eight pounds per barrel and their low grade two or three or 
four barrels per hundred, by doubling the number of wheat cleaning 
machines in the mill. Yet this is just the thing that was done, and with 
the result here stated. 




GRADUAL REDUCTION MILLING. 


375 


Within this last year or two we have all seen a number of horizontal 
•scouring machines come into the market—machines with horizontal 
•shaftings, or those which may be driven directly from a horizontal shaft. 
Such machines have met with great favor, other things being equal, with 
the millwrights, in that it does away with almost the only necessity for 
an upright shaft in a mill. During modern times such shafts have been 
decreasing in number until now we have mills which entirely dispense 
with their use—certainly a very agreeable condition of things. Scour¬ 
ing machines which have the vertical shaft, that is, the upright machines, 
have points in their favor, which statement might be made in regard to 
any machine; or it might be said, on the other hand, that the horizontal 
machine had points against it. It may be remembered, as a general 
statement, that every machine is a compromise. There is a compromise 
in the roller machine as compared with the millstones; there are points 
of excellence which distinguish each of these machines one from an¬ 
other. But to return to the horizontal cleaning machine: One thing 
which may be said in its favor is on account of the rolling action, the 
natural scouring action which it may be made to have in the treatment 
of the grain. 1 here is the throwing of the grain against the side of the 
cylinder, its rolling down, and its throwing back again. In the upright 
machine the gravity action is not materially instrumental in scouring. 
It, as a general thing, merely has the effect of getting the wheat from 
the machines. The writer does not wish to express any particular 
preference for the horizontal machine, but merely mentions this point 
as one which occurs to him. 

As mentioned once before, one great reason why the larger mid¬ 
dlings (those which will pass through a oo and ooo cloth) are not puri¬ 
fied or aspirated, is that they do not show to the eye the beneficial ef¬ 
fects of purification that the finer middlings do, though the result is very 
marked when we consider the amount of material which may be re¬ 
moved therefrom, and the yield of high grade flour which may be de¬ 
rived on account of their increased purity. For the same reason, it may 
be said that wheat cleaning methods are not followed up with the same 
vigor or the same interest. Wheat does not show as great a change in its 
appearance after it passes through the wheat cleaning machines as it does 
after it passes through other machines in the mill. That is, the changes 
to the eye are not so great, though there is no place in the mill wherein 
the general results can be affected more appreciably or more nrofitab 
(24) 


3 76 


GRADUAL REDUCTION MILLING. 


The writer thinks that he notices a difference in the wheat cleaning 
methods of the winter and spring wheat sections; notably, in the scour¬ 
ing of the wheat. There has been a greater tendency in the millers of 
the latter section to treat the grain more severely, to use machines which 
handle it more vigorously than do the millers of the winter wheat re¬ 
gion. One reason for this, as understood, is that spring wheat needs 
more cleaning, or rather shows the effects of cleaning more plainly than 
does the winter wheat. There is more in the spring wheat to take out 
by the cleaning machinery, and for that reason it receives more atten¬ 
tion. This leaves the miller to plan and to work and think more about 
what he is doing. Without increasing the number of operations in the 
wheat cleaning part of the mill, its severity has been increased in a large 
number. It would appear that the methods which accomplish the re¬ 
sults with the least absolute fracture to the bran are the ones to receive 
the greatest attention, to be most economical and most certain to meet 
with permanent and lasting favor 

We hear very little about systems of wheat cleaning as compared with 
systems in other parts of the mill. In the future we will hear more 
about wheat cleaning systems. Combination machines will certainly do 
more good as devised for wheat cleaning than for most other operations 
of the mill. The combination idea for a wheat cleaning machine is en¬ 
tirely feasible. It consolidates the mill and is economical. 

Having followed the wheat to the first reduction bin, we may go with 
it a little farther on its way to the reduction rolls. The next thing pos¬ 
sible and advisable to do is to pass it through wheat heaters. They are 
another of the indirect purifying agents—indirect in that they do not 
make an absolute separation, yet they render a separation possible. 
They toughen the bran by drawing the moisture from the interior of the 
berry to the outside, thus making the interior dryer and more brittle, so 
that it yields a larger proportion of middlings. Wheat heaters are hard 
to take care of. They require a good deal of attention in order to keep 
the wheat uniformly heated. Drips from the various connections is one 
of the things which make wTeat heaters obnoxious. 

One of the great points of difference which will be noticed in the de¬ 
scription of the 50-barrel mill will be the effort to produce a smaller 
grade of middlings by using somewhat finer corrugations for the first re¬ 
duction, and finer ware for the scalpers. The elaborate preparations 
which are necessary to take care of very coarse middlings can not be 



GRADUAL REDUCTION MILLING. 


377 


included in a plant of this size, and while it is not usual to make a dis¬ 
tinction in the size of the middlings according to the size of the mill, 
it is better, for all reasons, including the quantity and quality of the 
flour, as well as the cost of the plant, that this be done. 



CHAPTER I.XXI. 


BREAKS FOR A 50-BARREL MILL-CLOTHING OF SCALPERS-FIRST BREAK. 

As has been the practice, we give a fragmentary diagram which con¬ 
siders that part of the mill which is under immediate consideration. It 
would be entirely possible to give, in formulated shape, the length ol 
the rolls, their number, the numbers of the reels and their kind, and a 
list of the other machinery, and then say that the mill was planned on 
the same general scheme as the others which have preceded it. There 
are reasons for not doing this. First, every one has not read and may 
not feel inclined to read all that has gone before. Then, again, there is 
always something to learn, by the writer, at least, by going through 
these diagrams and giving the reasons for the faith there is in them. 
The reasons for a fact or a conclusion are often more valuable than the 
fact or conclusion itself. The reasons which lead one to adopt one sys¬ 
tem rather than another for milling, lead one to consider more intelli¬ 
gently and more thoughtfully the practical handling of the methods 
which h tve been logically deduced. 

In considering the run of the stock in the mill as it has been done in 
these chapters, there has been developed almost unconsciously a system 
which applies to all mills; that is, a milling system, and at the same time 
that it has been here developed and in this connection, it can not be 
claimed that it is an individual system, or one for which the writer is 
entitled to any credit. He has tried to connect and systematize the 
experience of others as well as his own, and has never hesitated to set 
aside individual ideas and individual preferences. As to the system: 
It may be said that it has been given in detail at other times, and per¬ 
haps with more detail, with finer classifications than are readily percepti¬ 
ble. Given in the rough, it would appear as follows: First break stock 
from the corrugated rolls, which is flour, middlings and dust middlings. 
As a tail from the last corrugated roll, there is the feed. From there is 
the purified stock from the tailings. From the reduced middlings there 
is the patent fiour, dust middlings and tailings. From the reduced tail¬ 
ings there is clear fiour, red dog stock and a low grade of dust mid- 














GRADUAL REDUCTION MILLING. 


379 


oo BFEAY, ft" W wm SWAGE. 

oomsKwm^Tom \\\cw nwwi 
WUL,m«\\VL^^ TO. SWtoTtt 


90WWI 


N 3 
\ 3 ' 


24 

21 


-+- 


2?*d Er 


\A- CUGTW 


\0 \_OYUS 




mi > 


00 SE.CONO BREAK S' ®\W SURFACE 
Viemm'WOHS 10 TY\E VWCH 


6' UMi 


dlings. Then there are the dust middlings which, when reduced, make 
clean Hour, and a cut-off which is the second dust middlings and that 
which goes to the red-dog. Then there is the reduction of the red-dog, 
which produces low grade Hour 
and fine feed. This is all there is 
to any mill, and on this scheme 
a successful mill of 50 or 5,000 
barrels a day may be constructed. 

The elaboration is a matter of 
detail, and does not affect the 
principle. 

For the diagram : It will be 
noticed that the first break is 
clothed with a short piece of No. 

90 wire. No. 90 wire is equal to 
No. 8 bolting cloth. The stock 
from this reel may be sent to a 
short reel clothed with No. 14 
cloth, or it may be sent direct to 
the red dog stone. The reasons 
which would prompt the running 
of this stock direct to the buhr 
would be those which had the 
strictest regard for the cost of the 
plant, rather than reasons which 
had in mind the best results when 
viewed from a business stand¬ 
point. The tail of this first break 
scalper is clothed with No. 24 
wire. It is well known that this 
is much finer cloth than is usually 
put on the scalping reel of this 



VQ GJRVtoVto swage. 


6' LOWS 






\ft ftWURATtoWS 


r«m 


24 - 


w\re 


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VAftS SGAtfER 


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YL 


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1ui . 



break. The reasons for this have 
been explained before, wherein 
it was stated that the middlings which ran through the 18 wire, which is 
the usual number, were coarser than could be economically handled in 
a mill of this size. An 18 wire equals a 0000 silk, and it is well known 
that the middlings which will pass through a 0000 cloth are nubs—ends 






































GRADUAL REDUCTION MILLING. 


380 

of wheat—middlings .with adhering portions of bran. It is not possible 
to properly take care of this stock on a mill of this size. Thus the 
effort is made not to produce it. The No. 24 wire would allow a grade 
of middlings to pass through which is neither so fine as 00 nor so coarse 
as 000, and is a grade which may be readily handled on a mill with this 
capacity. 

To go back a little, it may be noticed that the first break rolls have 8 
inches of grinding surface, and that one roll has four corrugations to the 
inch and the other is smooth. This sort of a dress to the rolls, or rather 
this arrangement, appears to meet with more favor than any other at 
this time. A break made by such a combination appears to be some 
little better than by the other methods. On first thought it would ap¬ 
pear that 2 feet for the tail cloth of the second break scalper was hardly 
enough, but when it is remembered that a scalper 6 feet long will sepa¬ 
rate the middlings on a 500-barrel mill, that is, those made on the first 
break of such a mill, it cannot be consistently maintained that this would 
appear to be too short for a 50-barrel mill. 

The second break has twelve corrugations to the inch, and the same 
number of wire on the scalper as mentioned for the first. It is usual to 
progress in fineness of cloth from the first break. The reason of this is 
that it is usual to take out the coarsest middlings made at each reduc¬ 
tion, and as the coarsest middlings are on the first reductions, the coars¬ 
est scalping cloth is there used; and as the middlings decrease in size, 
the grading cloth also decreases in fineness as it progresses toward the 
end. But, as said before, and as there explained, we do not take out 
the coarsest middlings made on any reduction until we get to the fourth. 
We merely take out the middlings that we want, and as the coarsest we 
care for are those which will pass through a No. 24 wire, we use nothing 
coarser than that number. As middlings are made on all the breaks to 
and including the fourth which are that large, we continue to use No. 
24 wire throughout the course of that part of the mill. The fact that 
the middlings coarser than those which will pass through a No. 24 wire 
are run from one break to another—that is, from the first to the second, 
and the second to the third, and the third to the fourth, and so on, will 
give these breaks a little more to do than they would have under other 
circumstances. It is taking stock which has been once reduced, and 
reducing it a little finer. The corrugations of the first three breaks 
naturally make a grade of middlings which are larger than those which 


GRADUAL REDUCTION MILLING. 


331 

will pass through the No. 24 wire, that is, none of the stock which 
should not properly go there will be seen passing over the tail of that 
Teel to the fifth break. 

It will be noticed that the grinding surfaces of the first two breaks are 
the same, and that we have 10 inches for the third and 12 inches for the 
fourth. This is a progression not common, it being usual to have the 
same number of inches for both the third and the fourth. Another 
thing, and that to which attention has been called many times before, is 
the increased length of scalpers, one to another. We have seen scalp¬ 
ing chests made with five and six reels in them, depending on the num¬ 
ber of breaks, all of which were of the same length. Now while it may 
be desirable to have the first break scalper a little longer than is neces¬ 
sary, for the benefit of the scouring and disintegrating action, it is not 
•desirable to have the other break scalpers any longer than is actually 
necessary to take out the middlings, and it is apparent that any reel 
which would simply take out the stock for the second break would be 
too short for the fourth or the fifth, and that if it were long enough for 
these freaks, it would be so long that the second and third breaks would 
be submitted to a scorning and pulverizing action on the additional and 
iimnecessarv length of reel. 

j 


CHAPTER LXXII. 


PURIFICATION OF MIDDLINGS IN 50-BARREL MILL— CLOTHING OF PURI- 

FIERS—PRODUCT OF ASPIRATORS—FIRST MIDDLINGS-MACHINERY FOR 

50- BARREL MILL—MILLSTONE REDUCTIONS IN 50-BARREL MILL. 

It has always been the custom to take up the purification of the mid¬ 
dlings after the consideration of the break stock, and in this instance, as 
in others, a sieve grader is used. The middlings are graded over Nos. 
4, 2, o and 00 cloth, which makes five grades of middlings; that is, one 
grade for each number of cloth, and one grade which passes over the 
tail of the oo cloth. Each grade of middlings passes through an aspi¬ 
rator on its way to the purifier proper, or to the sizings rolls. It will be 
noticed that the product of the No. 4 and No. 2 cloth, that is, the two 
finest grades of middlings, go to sieve purifiers. Because this mill is- 
small, and because a plant of this size does not justify more elaborate 
arrangements, we would suggest that the purifiers which take this class- 
of stock be double machines. By so doing there will be no particular 
sacrifice of principle. There is nothing wrong in using a double ma¬ 
chine when the middlings which pass to both sides are of the same grade 
and same general quality. 

In the matter of the clothing of these first two purifiers, the writer re¬ 
fers to what has been said before in regard to their clothing. All remem¬ 
ber when there was some mystery supposed to be connected with the 
clothing of purifiers and reels, but by this time most of us are satisfied 
with the fact that the clothing of machines and reels is a matter of 
almost common knowledge, founded on fixed principles. The clothing, 
of a machine which is intended for bolting or purifying purposes is in¬ 
fluenced entirely by the size of the stock to be handled. For instance, 
take this first purifier. The middlings which pass through the No. 4 
cloth originally passed over a No. 8 or No. 9 cloth on a grader, therefore 
the middlings which pass through the No. 4 cloth on the grader will be 
of a size represented by the numbers from 8 to 4 inclusive; and for that 
reason the extreme numbers, head and tail, of the machines which han¬ 
dle that grade of middlings, will be represented by the extreme num- 






GRADUAL REDUCTION MILLING. 


bers mentioned. For instance, there will be No. 8 at the head, which 
is the finest, and No. 4 at the tail, which is the coarsest. It will be no¬ 
ticed that on the first machines which handle the middlings of this grade 
is sometimes put a number a little coarser than the grading number, 
which is done to cover contingencies of occasional overloading. How¬ 
ever, we never use a number coarser than the grading number of the 
tail of the second machine. Any portion of the cut-off, if there be any, 
of the first machine, may be sent to the tailings. In this way the quality 
of the middlings going to the first machine may be exactly regulated so- 
that the last cut-off from the bottom machine may be sent to the head 
of the machine which handles the last grade of middlings. The mid¬ 
dlings which pass through the No. o and No. 00 and over the No. 00 
are purified on aspirators, and, as has been said before, it can be well 
and.economically done in that way. In fact, when these middlings are 
sized, as they always should be, there is nothing better to do with mid¬ 
dlings of this grade. There is no machine which is better calculated to- 
purify them and do it economically than these aspirators. It will be 
remembered that there is a very small amount of the middlings coarser 
than a co in this mill, this matter being regulated by the clothing of the 
break scalper. 

The product of the aspirators which handle the two coarsest grades 
of middlings, that is, the stock which goes through and over the No. 00 
cloth, is run together to the first sizing rolls, and is sized down from No. 
00 to o middlings. This sized stock is dusted over a No. 7, and the 
product of the No. 7 is run into a reel which separates the Hour from 
the fine middlings. The middlings which pass through the No. o cloth 
on the tail of this reel go to the next sizings rolls, and the tail of the 
No. o cloth goes to the tailings rolls. The product of the No. o cloth, 
of the grader and the product of the No. o cloth of the first sizing reel 
go to the second sizings rolls, where the No. o middlings are reduced to 
the size of the next grade of middlings on the grader, that is, the No. 2 
cloth. The same process of separation is repeated. The product of 
the No. 7 cloth of the scalper is sent to the dusting reel shown below 
on the diagram, while the coarse middlings, having all been reduced to 
No. 2 middlings, are sent to the sieve machines, which handle that grade 
of middlings. Thus we have our large middlings aspirated in the first 
place, then sized and scalped twice, and finally repurified before going 
to the first middlings rolls. The product of the No. 7 cloth of the two- 


GRADUAL REDUCTION MILLING. 


384 

scalpers, as said before, is sent to a reel which takes out the dust. This 
•dust is patent dour, and the product of the No. 6 cloth on that reel is 
.a most excellent quality of purified middlings, which are sent to the first 
middlings rolls. 

The first middlings rolls take the product of the first two series of 























































































































































































3§5 


■GRADUAL REDUCTION MILLING. 

•machines, that is, the first four purifiers, and break the middlings again. 
It is more of a sizing operation than a positive reduction, and should 
be so regarded in the operation of the mill. For this reason a No. 3 
cloth is put on the tail of the reel which handles the stock from these 
rolls. 1 he product of the No. 3 cloth is sent to a millstone which re- 
■duces this stock to patent Hour. The middlings here are called dust 
middlings. 1 his may be hardly proper, though the dust middlings were 
run into this stock. This stock is reduced by the millstones, and the 
product is patent flour. The product of the No. 9 cloth goes to the 
red-dog. If it is desirable to make this mill a little more complete, 
which would be advisable, a better thing to do than is here shown would 
be to have an extra millstone for the purpose of reducing the middlings 
from the first middlings rolls, and another millstone for the purpose of 
reducing the dust middlings, and then the product of this reel might go 
to the millstone red-dog reduction. 

The tailings from this mill run in a body to the tailings rolls. A good 
thing to do in a mill of this size would be to pass these tailings to an 
aspirator on their way to reduction. The stock which the aspirator 
would take would be the right kind of stock for feed. The flour from 
these tailings, which is bakers’ flour, and the cut-off, or so much of it as 
is good enough, may be run to the dust middlings, while the tail may be 
run to the feed, probably through a bran duster. 

In the drawing it is intended to show centrifugals where a horizontal 
line is drawn through the reels. 

We can not use the same number of reductions or so elaborate a sys¬ 
tem of reductions and separations for a mill of this kind as for one of 
larger size. The use of millstones for the reduction of the middlings, 
and of centrifugal teds for the separation of all grades of stock from 
which flour is taken, helps to simplify and shorten the general process. 
For this reason such devices are largely used. The following is a list of 
machinery used in this mill: 

Wheat Reductions—First break, 8-inch grinding surface; second 
break, 8 inch grinding surface ; third break, 12-inch grinding surface; 
fourth break, 12-inch grinding surface; fifth break, 14-inch grinding surface. 

Smooth Roll Reductions—Sizing for Nos. 00 and 000 middlings, 
8-inch grinding surface; sizing for Nos. 2 and o middlings, 8-inch 
grinding surface; middlings reduction rolls, 14-inch grinding surface; 
tailings reduction rolls, 8-inch grinding surface. 


-S6 GRADUAL REDUCTION MILLING. 

Millstone Reductions—Second middlings, i pair; red dog, one pair.. 

Reels—Five break scalpers, 3 sizings scalpers and 1 middlings, 
scalper. 

Flour Reels—One break dour centrifugal, 1 tailings centrifugal, 1 first 
middlings centrifugal, 1 dust middlings centrifugal and one red-dog cen¬ 
trifugal. 

Purifying Apparatus—One grader and 2 double sieve purifiers. 

Summary—Five pairs of corrugated rolls; 4 pairs of smooth rolls; 2 
pairs of millstones; 8 scalpers—short; 1 middlings scalper, 10 feet 
long; 6 centrifugals, 6 feet long. Purifiers: One grader and 2 double- 
purifiers. 

The above schedule includes as small an outfit of machinery as is. 
possible in a mill of this size, and, in fact, this is as small as a mill can 
well be and yet carry out the principle of gradual reduction. 

A mill of the kind here considered, and properly programmed with, 
the machinery here set forth, can do good work, make good flour and 
clean feed—so much so as to be able to enter into the general markets* 
for competition. One reason why this mill can do the work on the 
small amount of machinery here laid out is that in the programme it 
is arranged so that there is not a large proportion of large-size 
middlings to be taken care of, which will shorten, very materially, the- 
work of the reduction machinery. The number of reductions for 
the purpose of getting this stock into flour is materially diminished 
thereby. It is coming to be known more and more that smooth rolls 
can only go about so far in the reduction of flour stock or in the reduc¬ 
tion of middlings, from that of one size to a size smaller, and that any 
effort to hasten that operation defeats itself; that in so far as a reduc¬ 
tion be attempted beyond the proper point, in that same proportion will 
the labor of finally reducing this stock to flour be increased. Thus, if 
middlings be crushed down rapidly, as is the expression, they will be 
crushed, but not reduced to flour. They will be flattened, hardened,, 
and the labor of getting that stock into flour will be largely increased by 
this effort at rapid reduction. Thus if the middlings are small, there is 
necessarily less work to do. As has been illustrated before, no matter 
how careful the miller may be in the reduction of stock by smooth rolls, 
there will come a time when it is next to impossible to go farther in the 
direction of making flour by the use of smooth rolls—a point where re¬ 
duction by millstones appears to be a necessity. Say we take the reduc- 


GRADUAL REDUCTION MI LUNG. 


3S7 


tion of middlings of a grade from Nos. 2 to 00. By the time that the 
(roller machinery—that is, the smooth rolls—reduce this stock so that it 
will pass through a No. 6 cloth, or perhaps a No. 7, it is found that the 
middlings are as nearly purified as they ever will be, and, at the same 
time, that farther reductions by smooth rolls would merely harden the 
stock without making the desired amount of dour at a single reduction. 
The middlings being as pure as they well can be when of this grade and 
size, it is proper and economical that such middlings be reduced on mill¬ 
stones. Such a practice is sustained by the mistakes of roller reduction 
in this country, and by the general practice and recognized methods of 
the Hungarian mills. We have all talked all-roller mills to a greater or 
less extent ever since the introduction of gradual reduction methods. 
The idea is a very fascinating one; but all the time during the efforts 
which have been made to realize the proper results from such mills, the 
difficulties enumerated above—the difficulties in the complete reduction 
of the stock, have made themselves felt. 

It is a common expression among many of the best millers of this 
country that the millstone still has a place in all first-class gradual reduc¬ 
tion mills, and that gradual reduction does not, in theory or practice, 
forbid the use of the millstone. Gradual reduction has in mind the 
preparation of pure stock for final reduction. The middlings having 
been prepared and purified to the limit of possibilities, and having been 
reduced for that purpose, it is right and proper that the millstone be 
used to complete the reduction of this stock. Much of the stock which 
goes to the red-dog is in a condition to successfully resist the action 
of smooth rolls, hence the millstones are a necessity here. The writer 
thinks that he witnesses a general awakening on this point all over the 
■country. Every miller whom he has seen and to whom he has talked, 
for some time, confirms this idea. Smooth rolls will go farther in the 
reduction of hard wheat stock without hardening or flattening it than 
they will on the soft stock. Hence, there is a greater necessity for mill¬ 
stone reductions on winter than on spring wheat. Nevertheless, spring 
wheat millers have been talking of this matter for some time. 





























. 

























. 







































A FIVE HUNDRED BARREL MILL. 













CHAPTER LXXIII. 


WHEAT CLEANING OF 500-BARREL MILL-WEIGHING OF WHEAT-SUCTION 

OF DUST FROM WHEAT—WAREHOUSE SEPARATOR—WEIGHING OF WHEAT 
FROM SEPARATOR BINS-ROLLING SCREEN—MAGNET—WHEAT SEPARA¬ 
TORS-COCKLE MACHINE—SMUTTERS—WEIGHING OF WHEAT TO CLEAN 

WHEAT BINS. 

We will now take up the consideration of a mill of about five hun¬ 
dred barrels capacity, but, as said before, it is difficult to decide upon 
and arrange a system which is applicable, in the proportioning of the 
different parts, to all sections of the country and the various kinds of 
wheat. A mill which will make five hundred barrels of flour on one 
kind of wheat, may make more or less on other kinds. Furthermore, 
on one kind of wheat a larger amount of a particular kind of machinery 
may be necessary for its reduction and separation than on other kinds 
of wheat. For instance, a mill planned to work on a medium grade of 
winter wheat and do its work well at each particular stage of the pro¬ 
cess, might have more machinery than is necessary at one stage of the 
operation and less at others, when applied to the milling of California 
wheat of the harder varieties. Due allowance, therefore, has to be made 
in considering diagrams and formulas which are made from a particular 
standpoint. 

We will begin a little earlier in the process of milling than has been 

common in the consideration of the other diagrams, and commence with 

the weighing of the wheat. In many mills the scales are placed at the 

bottom of the mill, though it is better that they should be at the top. 

and of a size to weigh in car-load lots. It is difficult to get scales of 

this size in the basement of a mill as ordinarily constructed, but without 

• 

going into details in this matter, which is more one of mill engineering 
than milling proper, we will simply illustrate by placing the wheat scales 
at the bottom of the mill, and from thence will indicate in a conven¬ 
tional manner the cleaning and handling of the wheat. Over the scales 
there is marked a suction hood from which dust may be taken as the 
wheat enters the scales. This suction is also connected below the 
(25) 


3 9 2 


GRADUAL REDUCTION MILLING- 


scales. This arrangement is more particularly for the purpose of general 
cleanliness about the mill, than for the distinctive cleaning of the vvheat r 
although it is an auxiliary process. The suction arrangement in and 
around the scales should present as little complication as possible, in 
order that it may not prejudice the _ 
sellers of wheat against the weighing 
apparatus. The hood should be ar¬ 
ranged so that it may be raised or low¬ 
ered. The suction under the scales 
would have the effect of keeping the 
working parts thereof clean, while the 
suction above makes it possible for the 
attendant to do his work without great 
discomfort, or the certainty of injury to 
his health. The same suction scheme 
is carried out at the head of the eleva¬ 
tor for the same purpose, and accord- 



SCALES 


ing to the same general plan as indicated below. Suction spouts of the 
kind shown can be connected with any conveniently located fan; and it 
is well that the force of the suction should be quite strong, as it is hardly 
possible to create waste at this stage of the process by an ordinary draft. 

The passage of the wheat from the 
elevator is shown on the diagram as 
being to the warehouse separator, the 
size of which would have to be deter¬ 
mined by the size of the scales, or the 
capacity of the elevator. Before the 
ninqs wheat goes to the stock bins it should 


St ROLLING SOREEN 



pass through a warehouse separator, in 
the manner here shown. As the wheat 
is wanted for use, it should be run into 
what is called a separator bin, immedi¬ 
ately over or in immediate connection 
with the cleaning machinery. This bin 
should be hoppered so that it can be 
drawn out clear every day, or as desired. Before the wheat goes into it, 
it should be weighed, in order to facilitate the taking of the yield on 
each dav’s run. 



















































GRADUAL REDUCTION MILLING. 


393 


From the separator bin the wheat goes first to rolling screens; but 
before going into consideration of the details of this operation, we will 
consider how much wheat there is to clean. In the first place, say that 
we make 500 barrels of flour, and in order to be on the safe side with 
the cleaning machines in estimating how much they have to do, say that 
we take five bushels of wheat to make a barrel of flour. This, however, 
is too large a figure, but this calculation gives us a margin. Five hun¬ 
dred barrels of flour at five bushels per barrel makes 2,500 bushels of 
wheat to be cleaned in twenty-four hours. If the cleaning machinery 
be run to its minimum capacity, and during twenty-four hours in the 
day, we would need two rolling screens, 36 inches in diameter and 14 
feet long; then there would be two of each of the other machines; that 
is, four separators, two cockle machines and four smutters of say sixty 
bushels capacity per hour each; or those of twice that capacity, which, 
however, would hardly do the work as well as the two. 

This would involve a plant which is larger than is usual for a mill of 
this size, but in this instance the arrangement for wheat cleaning is on a 
basis somewhat different from what is usual in mills as ordinarily con¬ 
structed. It is intended to carry out the idea of the gradual cleaning of 
the wheat as a part of the gradual reduction and gradual purification 
process, and as a part of that scheme, the limiting of the work to be 
done by each machine is considered necessary. If the wheat is cleaned 
gradually, a larger proportion of the objectionable material is removed 
from the stock, and at the same time a smaller proportion of the wheat 
itself will be taken out during the cleaning process, i. e., with the offal, 
the screenings, etc. It has been recently proved, as previously stated 
in this work, that the yield may be materially reduced by the gradual 
cleaning of the wheat. There will be less wheat going into the screen¬ 
ings, consequently more of it into the flour. The proportion of low 
grade is also reduced by the same means, in that the impurities are taken 
out of the wheat and do not have to be taken care of elsewhere in the 
mill. In this will be found a justification for the large plant of wheat 
cleaning machinery for a mill of this size. 

As said before, there will be two rolling screens, which are to be 14 
feet long and 36 inches in diameter. The head portion is clothed with 
wire to take out the screenings, and the tail portion with wire which will 
remove the coarse screenings by their passing over the tail, and allow 
the wheat to pass through the cloth itself It is suggested that this cloth 


394 


GRADUAL REDUCTION MILLING. 


be made of square wire instead of the round, in order that there be pre¬ 
sented to the wheat the square scouring edges of the wire. By dividing 
this stream and sending it through the screen, it is sufficiently thin so 
that the wheat may be well scoured. The scouring will be better done 
than if the wheat all passed through one reel and then through another. 
The wheat which leaves the machine passes through a magnet to the 
first separators through which it passes, taking out the coarse and fine 
screenings and the dust stock, and thence through other machines of the 
same kind which do the same work. This multiplicity of operations on 

a light feed admits of the careful and eco¬ 
nomical work of which we spoke. At the 
same time that it is economical, it is thor¬ 
ough. After the wheat leaves the separa¬ 
tors, and before it goes to the smutters, it 
goes through the cockle machines, at which 
point the round seed and other impurities 
of that form are taken out. From the 
cockle machines the wheat passes to the 
first smutters, or scouring machines, which 
remove the light and heavy offal at the 
same time that they scour the grain. It 
then passes through another smutter of the 
same kind, and thence through the magnets to the scales, whence it is 
weighed into the cleaned wheat stock bins. The weighing of the wheat 
in this way, before and after cleaning, indicates the proportion of loss 
by such a process, which is one step in the direction of giving a miller 
full knowledge of what he is doing, one day at a time. In this way there 
can never be anything wrong for a great length of time. By grinding 
out the bin every day and packing all of the flour from the packers at 
the same time, the proportion of flour of the various grades in connec¬ 
tion with the amount of wheat used is ascertained after the manner de¬ 
scribed in a recent chapter. 






















CHAPTER LXXIV. 


WHEAT HEATERS FOR 500-BARREL MILL-FIRST BREAK—REDUCTION AND 

SEPARATION OF FIRST BREAK—SECOND BREAK-THIRD BREAK-FOURTH 

BREAK-SEPARATION OF MATERIAL FROM 'IHREE MIDDLE BREAKS- 

ASPIRATORS FOLLOWING THREE FIRST BREAKS-SEPARATION OF FLOUR 

STOCK FROM SECOND, THIRD AND FOURTH BREAKS. 

On its way from the stock bins to the first break rolls it will be desirable 
to pass the wheat through wheat heaters as a means of toughening the bran 
and making hard and brittle the interior portions of the berry. This is 
done, as has been explained before, by drawing the moisture from the 
interior of the berry to the exterior, 
want—a tough bran coating and a 
more brittle interior, which will in¬ 
crease the product of middlings. An 
ordinary copper heater, one of the 
usual size, as now made, will not 
heat in a uniform manner more than 
fourteen bushels of wheat an hour, 
and for this reason it will require 
quite a large nuiyiber of heaters. 

One of the great troubles from wheat 
heaters is from leaky joints in the 
pipe which connects them. Con¬ 
sidering the large number necessary, 
it is almost impossible to have them all tight at once. Foi that reason 
it is well to have the heaters placed a little to one side of the rolls, and 
adjacent to which there should be a platform readily accessible from a 
short stairway, which would facilitate the regulation of the steam supply 
and consequently aid in preserving a uniform temperature in the wheat. 
All that is necessary is that the water of condensation should immedi¬ 
ately be carried from the heaters. It is not necessary to have a high 
pressure in order to get the greatest benefit from the steam. One pound 
of steam will do just as well as more. It is the latent heat which does 


Thus we will have just what we 




































39 6 


GRADUAL REDUCTION MILLING. 


the work in this instance, and the amount of such heat is greater on a 
low temperature than on a high one. As to the desirability of heating 
wheat before grinding, there is no question in the writer’s mind. It may 
be settled in the mind of every one who runs a mill, by carefully examin¬ 
ing and testing the Hour without the wheat heaters. 

From these heaters we come to the first break. At the present 
writing, rolls, one of which is smooth and the other having four corruga¬ 
tions to the inch, are the most popular for the first break. However, it 
is only a little better than the ordinary first break by rolls. There is no 
particular difference between this and other first breaks which have been 
described, excepting possibly in the matter of separations, which are 
somewhat more complete. There are four pairs of 9x18 rolls. The wheat 
which passes from them goes into a scalper 10 feet long, clothed with 
No. 20 wire. This scalper is somewhat longer than is necessary in 
making a separation, but in it there is an agitating action which has the 
effect of dislodging whatever crease dirt may be in the grains which have 
not been entirely broken. The tail of this scalper on its way to the 
second break passes to an aspirator. The stock which is drawn out 
goes to the feed pile. There will not be much of it, and as a matter of 
fact there is less necessity for aspirating the first break than any other. 
Still it is possible to aspirate that break with less loss than any of the 
others, for the reason that it does take out a little stock, which accounts 
for the popular prejudice in favor of so doing at this stage of the pro¬ 
cess. There can not be much stock to take out from the first break by 
aspirating. In the nature of the reductions there is little, if any, of 
what is known as “fly-wing” bran, and other light stock of similar char¬ 
acter. 

The product of the No. 20 wire goes into another scalper clothed 
with No. 6 cloth. This is done to separate the middlings from the 
flour before bolting it. The middlings which pass over the tail of this 
scalper are sent to the grader. They are of good quality, large in size, 
somewhat irregular in form, however, and contain a large proportion of 
germ. It is shown that a certain proportion of the product of this No. 
6 cloth may be sent directly to the red-dog. This is done in order that 
any of the red middlings stock which will pass through the tail of this 
reel need not be sent to the flour reel below. The product of the lower 
reel is, of course, low grade. The cut-off and tail from the reel go to 
he red-dog bin. 


GRADUAL REDUCTION MILLING. 


397 


"W e next consider the second break. We have the same number of 
rolls and the same length of scalper we had on the first break. The 
corrugations of the rolls are ten to the inch. The clothing of the scalp¬ 
ers is No. 20 wire, the same number that we use on the first break, which 
number is a proper one to use in connection with the ten corrugations 
of the second break rolls. 1'he tail of the second break scalper also 
passes to an aspirator on its way to the third break. In accordance with 
the general system in this mill,"the 


middlings from each scalper are 
dusted or scalped by themselves, 
that is, the middlings from each 
break are scalped separately. In 
the present instance it is done on a 
reel placed immediately under the 


2° BREAK 


9 X \!8 ROLLS 

CIO o 


O 




3° 


!0 COR 


C= 


!0 LONG 


20 W/RE 


8 


BREAK 


CO 

o o 

o o 

0 o 


12 

LONG 


■V 

22 

WIRE 

1 



0 oo 


- 


* F 

9 1 





scalping reel of the second break. 

This admits of an examination of 
the middlings being made on each 
break, which affords the miller ready 
means of determining as to the 
quality of its grinding on each par¬ 
ticular break. A great deal of bad 
work has been done by careless 
grinding and without knowing ex¬ 
actly where it was done. The 
arrangement of independent mid¬ 
dlings scalpers for each break facili¬ 
tates good grinding. Two conveyors 
are provided under this middlings 
scalper, so that any undesirable 
portion which passes near the tail 
of that reel may be sent to the 
third dust middlings. It is often the case that near the tail of a reel 
handling such stock as this, there may be found some very bad material, 
and this means of getting rid of it will certainly be very acceptable at 
such times. The general product of the reel, excepting what may be 
run off from the topTonveyor, is sent to the break flour reel. Another 
advantage in this methqd is to be found in the fact that the flour stock 
may be seen and examined in detail, the product of each break by itself. 






















































398 GRADUAL REDUCTION MILLING. 

The third break stock is reduced on six pairs of 9x18 rolls, each of 
which has fourteen corrugations to the inch. The break scalper from 
this third break is 12 feet long and clothed with No. 22 wire. The tail 
of this reel also passes through the aspirator, and from it quite a pro¬ 
portion of stock is removed. Altogether a great deal more is taken from 
the aspirator than from the other two. This is the last break on which 
an aspirator may be used. Its use on the fourth or other breaks would 
be wasteful. The product of the No. 22 wire is scalped in the same 
manner as is described in the second break; that is, the middlings are 
sent to a grader, and any undesiraole portion of the product of the 
scalping cloth is sent to the third dust middlings, while the general pro¬ 
duct of that cloth is sent to the Hour reel. Another thing which is 
gained by running off this stock which falls through the tail of the mid¬ 
dlings scalping reel, as is here shown, is in that it improves the quality 
of the dust middlings, which is very desirable indeed, as they are mid¬ 
dlings which can not be purified in the regular way, because they are too 
small—too light. In this instance it may be said they are purified by 
discrimination; that is, certain stock which would contaminate this ma¬ 
terial is run in another direction, and removed from the dust middlings. 

The fourth break has the same number of rolls as the third. The cor¬ 
rugations are sixteen to the inch. The scalping reel is 14 feet long, 
rather than 12, as was the case with the third break. This reel tails off 
to the fifth break, while its product goes into the scalping reel below, 
wherein the middlings are scalped and sent to the graders, and the Hour 
product is sent to the flour reels. 

Now we take the products of the second, third and fourth breaks and 
run them into the Hour reels, separating the stock in the manner shown 
in the diagram. It will be remembered that most of this material has 
passed through a No. 8 and No. 9 cloth, though in reels which contained 
large middlings. Therefore there will be some tail over the No. 8 on 
the first flour reel, as shown. The No. 12 cloth on that first reel pro¬ 
duces clear or baker*’ flour, as does also the flour cloth on the reels be¬ 
low. The tail over the No. 9 cloth, and any sharp portion of the pro¬ 
duct on the No. 8 cloth on the reel above, may be sent to the second 
dust middlings by running out this stock from the tail of this upper reel. 
The stock which goes into the second reel may be kept soft enough to 
bolt well by this means. The product of any portion on the No. 9 cloth 
on the second reel may be sent to the dust middlings after having been 



GRADUAL REDUCTION MILLING. 


399 


,rLDUR ST net FROM 2° 3 r r 


- 5 fr.S 


12 


is 


/ 


vibT 


J 2 


/V 


scalped on the reel above, and is sent to the reel below the first dust 
middlings. I he third reel, having had a portion of sharp material 
reduced by running out a large propor¬ 
tion of dust middlings on the second reel, C 
is in a good condition to produce a 
bright, clean hour. The tail of this reel 
goes to the first dust middlings, and the ^ 
cut-off which is the product of the No. 

T 4 or J 5 cloth, is sent to the second dust ^ 

Ui 

middlings tlour reel, which is better than o 
sending it on to the rolls, as it would there 
prevent the sharper stock from feeding 
properly. In any event, stock which is so fine can be readily reduced 
at a single reduction. Therefore, any portion of it which does not 
pass through the third dust middlings flour reel will tail over and be 
reduced on the third dust middlings rolls. 


i 


m 


16 




\ 

% 


^<6 



























CHAPTER LXXV. 


GRADERS FOR 500-BARREL MILE—METHODS OF REGULATING THE CAPACITY 

OF GRADERS—PRODUCT OF ASPIRATORS UNDER GRADERS-AN OUTLINE 

OF THE PURIFICATION SYSTEM OF 500-BAREF.L MILL. 

The diagram which is here given shows the means for the purification 
of the middlings from a 500-barrel mill. As has been indicated many 
times before, the middlings pass to a grader, or, as in this instance, to 
two graders. They are of the ordinary sieve type, such as has been 
described in previous chapters, and would here be 40 inches wide and 
20 feet long, which would give abundant capacity for the middlings from 
a mill of this size. The ordinary speed for such shakers is 275 revolu¬ 
tions per minute. 

It may be known that in some mills operating on hard wheat, about 
60 per cent of patent flour would be made, and in others operating on 
very soft wheat, 30 per cent, in which cases there would be a corre¬ 
sponding difference in the volume of middlings to be purified. The dif¬ 
ference in the capacity of the shakers would be regulated by the speed. 
In the event of their having too much to do, the speed could be 
increased above the speed indicated. The travel of the middlings is 
regulated by the throw of the shaker and the number of vibrations per 
minute. That is, the middlings will travel just so far for a certain vibra¬ 
tion. And if there be a greater number of vibrations, there will be a 
corresponding increase in the amount of stock which will pass over the 
shaker. Therefore, if the speed of the shaker should be increased to 
300 revolutions per minute, proportionately more stock could be han¬ 
dled on that shaker. As may be seen on the diagram, the middlings are 
graded into six grades. It will be remembered further that in the dia¬ 
gram of the break separations, the middlings were dusted over a No. 8 
cloth. Furthermore, that the coarsest break scalper was equivalent to 
No. 0000. Therefore we will have middlings coming on to this shaker 
which are as fine as the No. 8 cloth and as coarse as the No. 0000. 
Therefore there will be middlings passing through the No. 4 cloth at the 
head of the shaker which are as fine as No. 8 and as coarse as the grad- 



GRADUAL REDUCTION MILLING. 


401 


ing number, that is, 4. Next we will have those which pass through the 
No. 2 cloth, which are as fine as will tail over the No. 4 and pass 
through the No. 2, and so on. 

The sixth grade is made up of stock which will pass over the No. 
000. Now for each grade there is shown an aspirator which is common 


Purifications of M idilings joc o, Soo bbl M“ilt 

MidiJBTe&ks 7 *ojq' Grades 

111—_ V I # I 0 1 00 1 ooo- 11 



vtsf.Mzdsr 













































































































































































































































































































402 


GRADUAL REDUCTION MILLING. 

to all of these graders. The stock which passes over the slats is the 
middlings, and that which is drawn through is the tailings, which is indi¬ 
cated as passing to the rough tailings. This stock will be very poor in¬ 
deed. Very little material can be taken out through the first aspirator, 
or that which takes the middlings which pass through the No. 4 cloth. 
Such stock will be light, fuzzy material, not large in volume nor very 
bad as to its general character. That which passes through the No. 2 
and the aspirator in connection therewith will yield tailings of a quality 
somewhat lower than that of No. 4. It will be red and contain very 
little material which can be reduced to flour on the rough tailings rolls. 
When it comes to the stock which passes through the No. o and the 
aspirator in connection with it, the tailings which are drawn out will be 
almost poor enough for feed. It will be very .red indeed, and very light. 
The middlings which pass to the other purifiers will show very white, 
and will be quite free from the poorer class of impurities. The No. o& 
middlings will not show so white as the others, in that there will be mid¬ 
dlings therein which contain adhering portions of bran, and the tailings 
will be very poor, very red and very light. The same may be said of 
the No. 000 middlings. They will be correspondingly darker, and the 
tailings correspondingly poorer. The stock which passes over the No. 
000 and forms the sixth grade of middlings will contain a considerable 
portion of the red, foxy material which is passed along on top of the 
sieve. If there were odier better means of separating this material 
from the stock, it would be adopted, for the reason that it is hardly 
proper to run this stock which tails over the sieve and the large mid¬ 
dlings which go therewith, together. But as the middlings are very 
heavy, No. 0000 in size, and as the stock is very light, very little harm 
can be done by such a proceeding. The suction cn the No. 0000 mid¬ 
dlings may be quite heavy, and for that reason the impurities may be 
almost entirely removed. 

As said before, there are two of these shakers, with the correspond¬ 
ing aspirators. The stream is divided so that there are four machines for 
each grade, or two for each one shown on the diagram, the middlings- 
from each grader going to separate purifiers below. There is one set of 
machines for each grade excepting the last two, which run together and 
pass under the same machines. The arrangement of tails and cut-offs 
from these purifiers is somewhat different from that shown in the other 
diagrams. For instance, it has been common to run the cut off from 


GRADUAL REDUCTION MILLING. 


403 


the first machine of each series with the tail of that machine. Again, it 
has been usual to run the cut-off from the second machine of each 
series to the first machine of the next series. By reference to the dia¬ 
gram it will be seen that a different course has been pursued in this in¬ 
stance. 1 he tail of the first machine goes to the rough tailings, and the 
•cut-off from the first and the tail and cut-off from the second machine 
of each series go to fine tailings. This arrangement is common to all 
ot the purifiers. As to the aspirating purifiers, of which there are eight, 
the tail in each instance goes to the rough tailings, as does aho the por¬ 
tion which is drawn through the slats. 

Before considering this diagram in detail, it may be well to consider 
its general purposes and the general arrangement with that object in 
view. In that way it will be more easy to understand what is intended. 
In the first place, it is intended to pass the middlings of the various 
grades as they go through the graders, through the purifiers. Then it is 
intended to commence with the coarsest grade of middlings, and by 
gradual sizing to reduce all so that they will pass through a No. 7 cloth. 
This necessarily has to be done in a gradual manner, as it will be impos¬ 
sible to reduce coarse or other middlings more than one or two numbers 
at a sizing, unless it be the finer grades, which may be reduced three, or 
in some instances four numbers. But with the coarser grades this thing 
is impossible. There is an intermediate purification between each 
sizing; that is, the middlings of the coarsest grade, after having been 
sized or reduced, are purified on the machines of the next finer grade. 
All of this will be made clear in the detailed description. 


CHAPTER I, XXVI. 


PURIFICATION SYSTEM OF 500-HARREL MILL—GRADING, SIZING AND RE¬ 
PURIFICATION OF STOCK—DUSTING OF SIZED MIDDLINGS. 

We take the middlings which pass over the No. 4 cloth on the grader, 

* 

and which pass to the first machine of the fn>t series. This machine is 
clothed with Nos. 7, 6, 5 and 4. No. 7 is the number suggested by the 
cloth over which the middlings were originally dusted, that is, Nos. 8 and 
9. No. 7 will let through quite a proportion of the finer middlings. No. 
4, which is the tail number of this machine, is given from the grading 
number on the sieve grader above. The stock which passes over this 
tail number will necessarily be poor, as the sieve on the purifier will have 
more capacity than the corresponding sieve of the grader, in that the 
bulk of middlings will not be so heavy on the cloth, and again, the cloth 
will be kept cleaner. The better portion of stock which passes through 
the sieve is indicated as going to the second machine of the same series; 
that is, the first, and the portion which it is desired to cut off, is run to 
the fine tailings, then, again, the product of the next machine (that is, 
the one under the first, which is clothed with Nos. 8, 6 and 4—the finer 
number being suggested from the fact that we wish to carry the clean 
middlings a little further down on the sieve in the case of this second 
machine than we do on the first.) We may regulate the quality of the 
middlings taken from this second machine by the amount of cut-off 
which we take on the bottom conveyor. The product of this bottom, 
conveyor, together with the tail of this machine, is sent to the fine tail¬ 
ings. The product of the upper conveyor is purified middlings, and is 
sent to the first sizing rolls. The handling of the stock on the next 
machines is exactly the same as on the first, and the same principle is 
observed in the clothing of the machines as has been mentioned so many 
times before; that is, the finer number is made by the number over 
which the middlings pass, and the tail number by the number through 
which they pass. There is no guess-work in clothing a purifier, and 
should be none in clothing a reel. It may be determined by something 
which comes before or something which goes after. The No. o mid- 


405 


GRADUAL REDUCTION MILLING. 

dlings are purified in exactly the same manner as was shown in the other 
part of the diagram—that is, the first two series of machines. The mid¬ 
dlings which tail over the No. o cloth, and those which pass through the 
Nos. oo and ooo and which tail over the No. ooo, pass on to the aspi¬ 
rating purifiers, a distinct type of machines, and which we understand 
from what we have read of them before. In each instance it will be 
noticed that these machines stand alone. There is no connection from 
the machines which handle one grade of middlings to that which handles 
another. None of the stock which passes from one machine passes for¬ 
ward to another. After the middlings have passed from the purifiers, 
and have, as is usually understood, been purified—that is, after all has 
been done on them that can be done with the purifiers without sizing— 
the sizing operation commences. We first will take the middlings 
which pass through the No. ooo, and those which pass over the No-, 
ooo, that is, the coarsest grade. After they have passed through the 
two aspirators, and as we know, they will take out all that may be re¬ 
moved by a purifier, they pass on to the smooth rolls, the stock from 
which passes to a scalping reel clothed at the head with No. 7 and at 
the tail with No. 00. This No. 00 cloth fixes the setting of the rolls 
which size the middlings which go into this reel. There can be no 
change from this. If the rolls be set too close, the tail of the No. 00 
cloth will be rich, or if they be left open, it will be too rich. They must 
be set so that the stock which passes over the tail of this reel will be 
poor and can be run to the rough tailings, as is indicated, without waste. 
The product of the No. 7 cloth is sent to the Hour reels which separate 
the fine middlings from the Hour. The product of the No. 00 cloth 
goes to a grading reel below, clothed with Nos. 4, 2 and 00. It may be 
well to say here that these scalping reels and the grading reels which 
come under them should be set over the purifiers, so that the stock which 
passes through them may be run to the purifiers, saving the trouble and 
expense of elevating the stock. It must be understood that the ma¬ 
chinery in a mill cannot bear the same relation, one part to another, as 
is indicated in the diagram; for instance, where rolls are shown as com¬ 
ing above scalping reels, they more often come on the grinding floor 
kel ow — S ay some three or four stories below. We said that the middlings 
which pass through the No. 00 cloth on the first reel went into a grading 
reel immediately below it, and that this grading reel was clothed with 
Nos. 4, 2 and o. Then we take the middlings of each particular grade 


406 


GRADUAL REDUCTION MILLING. 


as made by this grading reel, and send them to the purifiers which have 
been described above as handling middlings of the sizes here named; 
for instance, the coarsest of these middlings, or that which goes through 
the No. oo, goes to the No. oo machine, and the next grade, which is 
the No. 2 middlings, goes to the machines which handle the No. 2 mid¬ 
dlings, and that which passes through the No. 4 cloth goes to the No. 
4, or finest grade of middlings. In each case there is a repurification of 
the middlings of the size indicated. The middlings are broken down, 
made finer, and then repurified. The middlings which pass through the 
No. 00 cloth go to the No. 00 purifiers, pass through those machines, 
come down on to another set of sizing rolls, and are then broken so that 
the coarsest will pass through the No. o cloth, or a number correspond¬ 
ing to the next finer grade of middlings, and the tail of the No. o cloth 
must, as said before, be stock which properly belongs to the rough tail¬ 
ings. The product of the No. 7 cloth goes to the reels before men¬ 
tioned, which separate the fine middlings from the Hour. Then, again, 
these middlings are graded, that is, the middlings which pass through 
the No. o cloth, and according to their grades are sent to the purifiers. 
This process is continued throughout. The middlings of the No. o 
grade have only to be graded into two sizes, that is, the No. 4 and the 
No. 2, there being only two grades of middlings finer than the one here 
mentioned. The middlings from the No. 2 grade require, after sizing, 
only one reel, as the tail number on that reel is the grading number on 
the next finer grade of middlings. The product of the No. 4 cloth 
passes to the machines which handle middlings of that grade. It 
will be seen that we have commenced with No. 000 middlings and 
gradually sized them, and at each sizing have graded them, and after 
each grading we have repurified them until we have all of a common 
size; that is, so that all will pass through a No. 7 cloth. Having scalped 
them after each operation, they cannot but be a very high grade of mid¬ 
dlings. It will be noticed in the practical operation of such a mill that 
the middlings which pass from the sizing rolls to the purifiers are of a 
better grade than the middlings which pass directly from the sieve grader 
to the purifiers. There is every reason why this should be so. In the 
first place, they have been purified after leaving the several graders, by 
the sieve machines, then they have been sized and scalped, each of 
which operations is calculated to, and does, remove impurities. 


CHAPTER LXXVII. 


TAILINGS FOR 500-BARREL MILL—FINE TAILINGS—COARSE TAILINGS- 

ROUGH TAILINGS—PURIFICATION OF FINE AND COARSE TAILINGS- 

SIZING OF TAILINGS—GRADING OF REDUCED TAILINGS STOCK-COMPOSI¬ 

TION OF ROUGH TAILINGS. 

We have spoken of coarse and fine tailings. The fine tailings are 
made up from the tail of the second machine and the cut-offs from each 
of the sieve machines of each series finer than the No. o grade, while the 
coarse tailings are made up from the No. o grade. Into the fine tailings 
we run the middlings from the fifth break. These fine tailings represent 
a quality of stock which in the smaller mills we have never been able to 
consider. There is a grade of stock in every mill, noticed by every one, 
which is neither middlings nor tailings. It is too good for tailings and 
not good enough for the middlings, and in ordinary operations on a 
small mill, each miller has to draw the line as pleases him best. He 
runs stock into the tailings which should not go there, and he runs stock 
into the middlings which he would run some place else if he could, but 
does not feel like running it in with the tailings. In a 500-barrel mill! 
there is an opportunity for distinct treatment, and if treated in the proper 
way, this stock may be purified and reduced so as to yield quite a pro¬ 
portion of good Hour. Under other circumstances it would be clear 
and low grade. The method of purification is somewhat the same as- 
with the general middlings above mentioned, excepting that all stock 
which is rejected either as a tail or as a cut-off is sent to the rough tail¬ 
ings, for there is nothing else to do with it. The fine tailings is next in 
grade to the middlings, the middlings being of a better quality and next 
to the rough tailings as well, such tailings being next purer in quality. 
The method of sizing is also the same as that of the middlings, except¬ 
ing that it is the object to reduce these middlings so that they will all 
pass through a No. 8 cloth, rather than a No. 7, as before. The first 
sizing operation is such as will reduce the coarser purified coarse tailings 
so that they will pass through a No. 2 cloth, which may be readily done. 
That portion which is not desirable to send in with the fine tailings 

(261 


408 


GRADUAL REDUCTION MILLING. 


is sent off with the rough tailings. The product of the No. 8 cloth is 
sent to a reel which will separate the middlings from the dour. The 
stock which passes through the No. 2 cloth on the sizing of the coarse 
tailings, or the desirable portion of it, goes to the fine tailings for 
repurification, and the fine tailings as they are purified go to their own 
sizing rolls, and are reduced so that the tail number may be 4, or the 
finest grade of fine tailings; and then the product of the No. 4 is sent 
to another set of rolls, which reduce it again so that the tail number of 
the reel under those rolls may be No. 6. Thus we have the middlings 
from the tailings of the better grade reduced so that all will pass through 
a No. 8 cloth. We take the product of the No. 8 cloth of each reel 
and run it to the reel which is designed to separate the flour from the 
middlings, which is shown in the diagram, which is clothed with a No. 
10, 8 and 6. The stock which passes through a No. 10 cloth goes into 
the flour reel below, or even a portion which passes through the No. 8 
may be sent in the same direction. The undesirable portion of the 
stock which passes through the No. 6 cloth may be sent to the rough 
tailings, if there be such portion, or all or any part of the No. 6 cloth 
product may be sent to dust middlings. The product of the flour 
from these reduced tailings middlings will be largely patent. A por¬ 
tion of it may be clear. The tail from the second reel is purified mid¬ 
dlings, which goes to the purified middlings bin. The quality of these 
middlings will be regulated by the quality of the stock which has 
been tailed off or cut oft' on the tailings purifiers, and the quality of the 
stock which has been cut off to the dust middlings on the upper reel 
here shown. But the middlings can hardly be so bad but that the stock 
which was sent to the purified middlings from the tail of this reel will be 
a most excellent quality, as will be the stock which is taken from the 
upper conveyor of this reel. Altogether it is an arrangement fur the 
purification of this intermediate grade of stock which will save it from a 
lower grade of material, a grade which would otherwise bring consider¬ 
able less money. 

At the head of each of the scalpers for the sizing rolls there is a No. 
7 cloth, the product of which is shown as going to a set of reels which 
are intended to remove the middlings from the flour. These reels are 
18 feet long, and, as shown, the first one is clothed with Nos. 9, 7 and 
6 cloth. The product of the No. 9 cloth is sent to the reel below, and 
the product of the Nos. 7 and 6 may be sent to purified middlings, or a 


GRADUAL REDUCTION MILLING. 409 

portion of the No. 6 cloth, if the quality of the stock warrants it, may 
be sent to the rough tailings. It is hardly probable that this will hap¬ 
pen, however. The second reel is clothed with Nos. 12, 14 and 16, 
which produces patent flour. The cut-off and tail from this reel go with 
the desirable product of the Nos. 7 and 6 on the reel above, and repre¬ 
sent purified middlings of the best grade in the mill, and from which the 
best flour will be produced. Anything else which may be desirable to be 
understood from this diagram, is clearly shown in the diagram itself. 


CHAPTER LXXVIII. 


COARSE AND FINE TAILINGS-THEIR DEVELOPMENT INTO PURIFIED MID¬ 
DLINGS, FLOUR AND ROUGH TAILINGS-MEANS FOR REDUCTION OF MID¬ 

DLINGS IN 500-BARREL MILL—CHARACTERISTICS OF STOCK TO BE 
REDUCED— QUALITIES OF MILLSTONE REDUCTIONS ON MIDDLINGS— 
JUDICIOUS USF OF MILLSTONES —OLIVER EVANS’ IDEA OF MILLSTONE 
REDUCTION. 

In the completion of the chapter on the purification of middlings for 
this 500-barrel mill, we neglected to say that all the stock which went 
to the graders was finally worked into that condition wherein it was 
either purified middlings or rough tailings. The middlings were purified 
and the offal was run into tailings of the various grades, that is, either 
the fine, or the coarse, or the rough tailings; and that portion of the 
better grade of tailings, that is, the fine and the coarse, were purified 
and reduced, and repurified and scalped, until that portion of this stock 
which could be run off as purified middlings, or as dust middlings or 

other middlings, was so done, in a manner to leave only rough tail- 

% 

ings as a residuum or an unfinished product. Thus we do not have to 
create or arrange for additional reductions for tailings, as is frequently 
the case in mills of this size, where the tailings are so graded. This 
thing is accomplished by the purificaiion of this higher grade of tailings, 
and by the separation of the reduced material as is dictated by its qual¬ 
ity. It may be, as said before, either purified middlings, dust middlings, 
or other stock of lower character. 

Having finished what we have to say in regard to the purification of 
the middlings, it is in order that we consider their final reduction into 
Hour. Now, it should be known, these middlings were originally pro¬ 
duced by the corrugated rolls, and they were purified by the agency of 
the ordinary purifiers and the smooth rolls and scalpers which followed. 
A large portion of these middlings were reduced a number of times by 
the smooth rolls during the process of their purification and repurifica¬ 
tion, and for that reason they may be considered as smooth roll mid¬ 
dlings; that is, middlings which have been largely produced by smooth 





GRADUAL REDUCTION MILLING. 41 I 

rolls—broken down from the larger stock. Having been submitted to 
this operation a number of times, it would hardly be possible to further 
reduce it with any degree of completeness by the use of additional smooth 
rolls. There is a tendency, as we know, in all stock, after having been 
touched a number of times by these smooth surfaces, to become a little 
flat and somewhat feathery in character, so much so that it is hardly 
possible after such a number of operations to continue such reduction 
successfully; therefore we have decided in this instance to reduce the 
middlings for the first time after they have become what we will call puri¬ 
fied middlings, by millstones, after which operation we may again resume 
their reduction by the smooth rolls. The millstones have a tendency 
not only to reduce, but to liven the stock again, make it round and 
sharp, and to bring it into the condition which will admit of its further 
reduction by the smooth rolls. It is well that this millstone reduction 
should come at such a time in the stock when the proportion of impuri¬ 
ties is the least, as it will be when leaving the sizing rolls and the purifiers 
which we have mentioned. After another reduction there would be a 
smaller proportion of real middlings, for the reason that considerable 
Hour would be taken out, and the general bulk of material thereby 
reduced. 

Soon after the general introduction of corrugated and smooth rolls for 
the purpose of milling wheat, it became a generally accepted idea among 
many millers that a millstone had no place in a gradual reduction mill 
—that nothing but corrugated and smooth rolls, or scratch rolls, could 
be used, and the millstone by many was regarded as a relic of a barba¬ 
rous method of reducing wheat which was past. We have heard a 
great deal said about it by the roller mill people and others—that 
“There is a mill without a millstone in it,” and all that. This is an idea 
which had a good deal of fancy and a good deal of pride to back it, 
and it was an idea which cost a good many people considerable sums of 
money. Now, it may be possible to do without millstones in an ordinary 
gradual reduction mill, and a great many have abandoned their use 
entirely, but there is a feeling, which we recognize, and have spoken of 
before, that there is something wrong in this—that there is a place for 
the judicious use of millstones in any mill of this kind. In those as ordi¬ 
narily constructed, it is at the tail end of the mill, perhaps, but in a mill 
arranged as is this one, where the middlings are sized so many times in 
the course of their purification, a millstone reduction is entirely proper 


412 


GRADUAL REDUCTION MILLING. 

and right. Again, if middlings are properly treated on buhrs, their 
reduction thereby is not so barbarous a process, after all. We would 
suggest something of this kind: First, that the buhrs be balanced 
and dressed very carefully, that the surfaces be smooth, the furrows 
large in number, and that the speed of the buhrs be not more than 130 
revolutions per minute, say, for a 48-inch stone; and in the grinding by 
these buhrs, we would say that they should not be set close. It is not 
necessary that middlings which have been purified as have those which 
we have been considering, be mashed do*m by being ground very 
closely. It is antagonistic to the ideas of good milling that such a thing 
should be done. They should be ground as high as possible, in order to 
produce a clean Hour through a No. 12 cloth on the first reel. Now, as 
all of this stock has passed through a No. 7 or 8 cloth, most of it 
through a No. 7, it is easy to see that a vigorous reduction is not 
necessary in order to bring it down to the Hour numbers. Not only 
is it not necessary as a matter of reduction, but it is entirely wrong as 
influencing the character of that reduction. If we grind close, as close 
as we well can, or anywhere near that point on the middlings, we are 
doing what most people claim that the buhrs will do, that is, pulverizing 
impurities in all grades of stock alike. But we may grind so that only 
that part of the material which is susceptible to the action of the mill¬ 
stones will be reduced, and that the impure material, which is somewhat 
tougher in character, will hardly be changed as to its size, and for that 
reason will pass over the tail of the scalping reel of the middlings reel. 
High grinding on middlings represents one character of work, and low 
grinding an exactly opposite character. High grinding fulfills an idea 
of gradual reduction, in that it is gradual and does not reduce the 
impure stock, and for that reason has its place in any gradual reduction 
mill. 

It has been expected that something would be said in the course of 
this work about millstones, and the writer has looked around a good 
deal and has thought considerable as to what would be said, and as to 
what would be new and fresh on the subject, as well as what it would be 
proper to say. It is proper to say here that the experience of the author 
has not been entirely with gradual reduction machinery, that is, the 
roller machinery, but that his first training and first work was with the 
millstones, with which he had considerable experience. He has arrived 
at this opinion: That nothing better ever was said about millstones or 


GRADUAL REDUCTION MILLING. 


413 


about a millstone reduction than was said by Oliver Evans, who died in 
the year 1819. His expressions in regard to the principle of buhr 
grinding are abreast of the times. Nothing better has been given to us, 
and those who are using buhrs for reducing middlings and other stock 
in the gradual reduction roller mills, cannot do any better than read 
what has been said by Evans, and it is here presented. While it 
has been the intention to collect some of the best facts attainable in 
regard to buhr nulling and present them for the benefit of those who 
care to mill, or for the entertainment of those who are otherwise inter¬ 
ested, we will say that nothing better can be done than to repeat what 
Oliver Evans had to say, as published in the earlier editions of his 
book. 


CHAPTER LXXIX. 


QUOTATIONS FROM OLIVER EVANS—MODIFICATIONS OF EVANS’ DRESS- 
CONTROVERSY AS TO THE NECESSITY FOR A MILLSTONE DRESS. 

From these principles and ideas, and the laws of cential foiccs, I 
form my judgment of the proper draught of the furrows and the man¬ 
ner of dress, in which I find but few of the best millers to agiee. Some 
prefer one kind, and some another, which shows that this necessary pait 
of the miller’s ait is not 
yet generally well under¬ 
stood. In order that this 
matter may be more fully 
discussed and better un¬ 
derstood, I have con¬ 
structed Fig. 2. AB 
represents the eight 
quarter, CD the twelve 
quarter, and EA the 
central dress. Now we 
observe that in the eight 
quarter dress the shor t 
furrows at F have abou 
five times as much 
draught as the long ones, 

.and cross one another 
like a pair of shears, 
opened so wide that they will drive all before them, and cut nothing; 
and if these furrows be deep they will drive out the meal as soon as it 
gets into them, and thereby make much coarse meal, such as middlings 
and shipstuff or carnel. The twelve quarter dress appears to be better ; 
but the short furrows have about four times as much draught as the long 
ones, the advantage of which I cannot yet see, because if we have once 
found the draught that is right for one furrow, so as to cause the mea 


I ig. m . 

















GRADUAL REDUCTION MILLING. 


415 


Fig 2. 


to pass through the stone in a proper time, it appears reasonable that 
the draught of every other furrow should be equal to it. 

In the central dress EA the furrows have all one draught, and if we 
could once determine how much is necessary exactly, then we might 
expect to be right, and I presume we will find it to be in a certain pro¬ 
portion to the size and velocity of the stone; because the centrifugal 
force that the circular motion of the stones gives the meal, has a tend¬ 
ency to move it outward, and this force will be in inverse proportion to 
the diameter of the stones, their velocities being the same by the fourth 
law of circular motion. E e is a furrow of the running stone, and we 
may see by the figure that the 
furrows cross one another at 
the center in a much greater 
angle than near the periphery, 
which I conceive to be right, 
because the centrifugal force is 
much less nearer the center 
than the periphery. But we 
must also consider that the 
grain, whole or but little bro¬ 
ken, requires less draught and 
central force to send it out 
than it does when ground fine, 
which shows that we must here differ in practice from the theories 
founded on the laws of circular motion and central forces; because, the 
grain as it is ground into meal is less affected by the central force to 
drive it out, therefore the angles with which the furrows cross each other 
must be greater than the verge or skirt of the stone, and less near its 
center than assigned by theory, and this variation from theory can be 
formed only by conjecture, and ascertained by practice. 

From the whole of my speculations on this difficult subject, added to 
my observations on my own and others’ practice and experience, I 
attempt to form the following rule for laying out a five-foot millstone: 

1. Describe a circle with 3 inches, and another with 6 inches radius, 
round the center of the stone. 

2. Divide the 3 inches space between these two circles into 4 spaces, 
by 3 circles equi-distant; call these 5 circles draught circles. 















416 


GRADUAL REDUCTION MILLING. 

3. Divide the stone into 5 parts, by describing 4 circles equi-,distant 
between the eye and the verge. 

4. Divide the circumference of the stone into 18 equal parts, called 
quarters. 

5. Then take a straight-edged rule, lay one end at one of the quarters 
at 6, at the verge of the stone, and the other end at the outside draught 
circle, 6 inches from the center of the stone, and draw a line for the fur¬ 
row from the verge of the stone to the circle 5. Then shift the rule 
from draught circle 6, to the draught circle 5, and continue the furrow 
line toward the center, from circle 5 to 4; then shift in the rule to 
draught circle 4, and continue to 3; shift to 3 and continue to 2; shift 
to 2 and continue to 1, and the curve of the furrow is formed, as 1—6 
in the figure. 

6. To this curve form a pattern to lay out all the rest by. 

The furrows with this curve will cross each other with the following 
angles as shown in Fig. 1, at circle 1, which is the eye of the stone, at 
75 degrees angle, No. 2 at 45 degrees, No. 3 at 35 degrees, No. 4 at 31 
degrees, No. 5 at 27 degrees, and No. 6 at 23 degrees. 

These angles, I think, will do well in practice, will grind smooth, and 
make but little coarse meal, etc., as shown by the lines, G r, Hr, G s, 
Hs, etc. 

Supposing the greatest draught circle to be 6 inches radius, then by 
theory the angles would have been at circle 1, at 138 degrees angle, 
No. 2 at 69 degrees, No. 3 at 46 degrees, No. 4 at 34J4 degrees, No. 5 
at 27^4 degrees, and No. 6 at 23 degrees. 

If the draught circle had been 5 inches radius, and the furrows 
straight, the angles then would have been at circle 1 about 180 degrees, 
and 6 inches from the center, as shown by lines G 1, Hi, no degrees; 
No. 2 at 60 degrees, No. 3 at 38 degrees, No. 1 at 29 degrees, No. 5 at 
23 degrees, and No. 6 at 18 degrees. 

The angles near the center here are quite too great to grind; they 
will push the grain before them; therefore, to remedy all these dis¬ 
advantages, take the aforesaid rule, which forms the furrows, as shown 
at 6—7, Fig. 1, which is 4 of 18 quarters. HS represents a furrow of 
the runner, showing the angles where they cross those of the bed-stone, 
in every part. Here I have supposed the extremes of the draught to 
be 6 inches for the verge, and 3 inches for the eye of the stone, to be 
right for a stone 5 feet in diameter, revolving 100 times in a minute; 


GRADUAL REDUCTION MILLING. 


417 


but ot this we cannot be certain. Yet by experience and practice the 
extremes may be ascertained in time for all sizes of stones, with differ¬ 
ent velocities, no kind of dress that I can conceive appearing to me 
likely to be brought to a truth except this, and it certainly appears, both 
by inspecting the figure, and reason, that it will grind the smoothest of 
all the different kinds exhibited in the plate. 

The principle of grinding is partly that of shears clipping. The 
planes of the face of the stones serving as guides to keep the grain, 
etc., in the edges of the shears, the furrows and pores forming the 
edges; if the shears cross one another too short, they cannot cut. This 
shows that all strokes of the pick should be parallel to the furrows. 

lo give two stones of different diameters the same draught, we must 
make their draught circles in direct proportion to their diameters; then 
the furrows of the upper and lower stones of each size will cross each 
other with equal angles in all proportional distances, from their centers 
to their periphery. But when we come to consider that the mean circles 
of all stones are to have nearly equal velocities, and that their central 
forces will be in inverse proportion to the diameters, we must consider 
that small stones must have much less draught than larger ones, in pro¬ 
portion to their diameters. 

It is very necessary that the true draught of the furrows should be 
determined to suit the velocity of the stone, because the centrifugal 
force of the meal will vary, as the squares of the velocity of the stone, 
by the fifth law of circular motion. But the error of the draught may 
be corrected in some measure by the depth of the furrows. The less 
the draught the deeper the furrow, and the greater the draught the shal¬ 
lower must the furrows be to prevent the meal from escaping unground. 
But if the furrows be too shallow, there will not be a sufficient quantity 
of air pass through the stones to keep them cool. But in the central 
dress the furrows meet so near together that they cut the stone too much 
away at the center unless they are made too narrow; therefore I prefer 
what is called the quarter dress, but divided into so many quarters that 
there will be little difference between the draught of the furrows. Sup¬ 
pose 18 quarters in a five-foot stone, each quarter takes up about io^4 
inches of the cbcumference of the stone, which suits to be divided into 
about four furrows and four lands, if the stone be close, but if it be 
open, two or three furrows to each quarter will be enough. This rule 
will give 4 feet 6-inch stones 16, 5 feet 6-inch stones 21, and 6-feet stones 



4 i8 


GRADUAL REDUCTION MILLING. 


25 quarters. But the number of quarters is not so particular, but better 
more than less. If the quarters be few, the disadvantage of the short 
furrows crossing at too great an angle, and throwing out the meal too 
coarse, may be remedied by making the land widest next the verge, 
thereby turning the furrows toward the center, when they will have less 
draught, as the quarter HI, Fig. 2. 

This may be said about the sickle dress which Evans suggests, that 
where there is the small proportion of skirt which is now used, say 
about 9 or 10 inches on a 48-inch millstone, that the sickle curves are 
hardly necessary. The difference in the angle of their contact is hardly 
sufficient to justify the use of such a dress. However, a uniform draught 
under any circumstances should be used, and upon the general princi¬ 
ples which he outlines. Should we develop the sickle draught, if we 
connect a line 9 inches from the periphery of the stone with one at that 
point, we would have a proper draught. Or to express this another 
way, for the sake of clearness: Say we connect the two ends, the 
outer and the inner, of the furrow, with a straight line. 

Those who have read Professor Kick’s book, or translations from it, 
will probably remember an account of a controversy among some Hun¬ 
garian millers in regard to drafts of millstones. We here present the 
facts as they are given: 

In 1873 Franz Schmid made the experiment in Lanzendoif of grind¬ 
ing with the runner reversed in direction, and could not notice much 
difference in the ground material as to quality or quantity. 

This trial caused further examinations, and October 6, 1877, i n the 
mill of Adalbert Illavac, in Podiebrad, the matter was carefully tested. 
The stones used were French buhrs, with a diameter of 1.1 metres, and 
were divided in twelve quarters. The draft circle measured but eight 
centimetres in diameter, and every quarter had three furrows parallel 
to each other. Diameter of the eye of the stone, 26 centimetres; width 
of grinding surface, 19 centimetres. The shape of furrows and balance 
of stone were in perfect order. Three hundred litres (a litre is equal 
to about one quart) of first reduction stock was reduced to second re¬ 
duction, which resulted in : 

Regular direction of upper stone—Flour, 19.5 kilogrammes, 6 per cent; fine middlings, 10.2 
kilogrammes; coarse middlings, 22.8 kilogrammes; temperature,23 0 C. 

Opposite direction of runner—Flour, 25.9 kilogrammes, 8 per cent; fine middlings, 8.8 kil¬ 
ogrammes; coarse middlings, 30 kilogrammes ; temperature, 25-26° C. 

Coarse remnants were more broken. 


CHAPTER LXXX. 


REDUCTION OK MIDDLINGS IN 500-BARREL MILL — SEPARATION OF RE¬ 
DUCED STOCK—CLOTHING OF REELS—REDUCTION OF SECOND MID¬ 
DLINGS. 

Now lo take up the reduction of the midtilings by the millstones: 
We will presume that the grinding has been of the character that was 
previously described; that is, as high as can be to produce good flour 
and full length of the flour cloth on the first middlings reel. There are 
three 48-inch millstones for this purpose. This will admit of the possi¬ 
bility of the facing of one of them as it may be required, though better 
grinding will be done by the three of them at once. On the tail of the 
first reel it will be noticed that there is a No. 8 cloth, and if the grind¬ 
ing be of the proper character, there will be nothing but rough tailings 
pass over its tail. Also, there will be a proportion of this grade of stock 
pass through the No. 8 cloth near the tail, which may be run to the 
rough tailings by closing slides under that conveyor. Again, any por¬ 
tion of the product of the No. 14 cloth, or of the No. 8 cloth, may be 
run into the reel immediately below by opening slides. It may not 
always be desirable to take flour the full length of the upper reel, even 
if the flour is clean and bright during the full length of the flour num¬ 
bers on that reel. It may be desirable that the proper softness of ma¬ 
terial be preserved in the second reel in order that the flour from that 
reel be sufficiently bright and clean, as well as on the reel immediately 
under it. If all the flour were taken out which it is possible to remove 
on the first reels, it might be found that the flour which came from the 
second reel, or quite a proportion thereof, would be rather ragged and 
red in character. The No. 9 cloth which is on the tail of the second 
reel admits of the reduction of a proportion of soft material which goes 
into the third reel and at the same time conveys stock to the second 
dust middlings. Now, as the original middlings were No. 7, and as there 
was a reduction by the millstone, the stock which passed over the tail 
of this No. 9 cloth would still continue to contain branny, impure stock, 
and possibly a portion which went through the No. 9 cloth would also 







420 


GRADUAL REDUCTION MILLING. 

be of the like character, but this material could be kept up in quality, if 
desirable, by taking less Hour from the first reel. 

The cut-off and tail from the last flour reel is second middlings. 
Their reduction is accomplished by the use of three 9x14 smooth rolls. 
The stock having been reduced on the millstones, it is now in a condi¬ 
tion to be again taken up by smooth rolls, and it is particularly desirable 
that this be done, for the reason that the stock will hardly be so pure as 
second middlings as it was as first middlings, notwithstanding the fact 
that it has been scalped twice since its reduction. This is true for the 
reason that the proportion of middlings to impurities has been reduced. 
There are absolutely less impurities in the second middlings than there 
were in the first middlings; relatively the proportion is larger, that is, 
there are less middlings, but proportionately more impurities. The 
reduction of the middlings by this amount of grinding surface will 
pulverize a larger proportion of the material which it is desirable to pul¬ 
verize or reduce, and leave whole or intact that portion which is desira¬ 
ble, in the impurities. The tail of the No. 10 cloth will not be of as 
poor a quality as was the tail of the No. 8 cloth on the first middlings 
reel, and the proportion of soft material which goes into the second reel 
may be regulated in the same manner as was described for the first mid¬ 
dlings stock. The product of all the reels of the first and second mid¬ 
dlings is patent flour. The tail and cut-off from the last second 
middlings reel is first dust middlings, or it might be called third mid¬ 
dlings, excepting that the stock is of the same general quality as the first 
dust middlings, and is run in with that grade of stock. 


CHAPTER LXXXI. 


BREAK FLOUR REELS FOR 500-BARREL MILL-SEPARATION OF STOCK- 

FIFTH BREAK OF 500 BARREL MILL—CLOTHING OF REELS AND SCALPERS 

WHICH FOLLOW-SIXTH BREAK ON 500-BARREL MILL-CLOTHING OF 

REELS AND SCALPERS WHICH FOLLOW—A SEVENTH BREAK. 

The break flour reels, as here designated, handle the stock of the mid¬ 
dlings scalpers from the second, third and fourth breaks. The fifth break 
stock is handled by itself. The head number is 12, as usual, and the 
tail number on the first reel is 8. The tail of the No. 8 is a proper 
grade for the third dust middlings. The second reel is clothed on its 
tail with No. 9, and the tail of the No. 9 is of the proper quality for the 
second dust middlings. The cut-off from the first scalper is sent in the 
same direction. The clothing of the second reel is Nos 12 and 14. 
The quality of the product of the No. 12 cloth may be regulated by the 
proportion of the material which is cut off from the upper reel. If the 
stock which goes through the No. 9 cloth of the second reel should be 
too soft, it would remain to take more flour from the first reel, or if it 
were too sharp, it would take less flour from the first reel. Objection 
might be raised to the fact that we take a certain proportion of the No. 
9 cloth product and send it with the second dust middlings rather than 
with the first. But it may be said that the object in this case is to keep 
the first dust middlings as bright and as clean as possible, and again, 
that the quality of this stock which goes to the second dust middlings 
can be regulated at will by the miller by the adjustment of the slides 
under the scalpers. The clothing of the third reel is with Nos. 14 and 
16, which will admit, under ordinary circumstances, and the proper 
treatment of the reels above, of taking the flour the full length of that 
reel; or, if not its entire length, most of it. There is a disposition to 
reject No. 16 cloth by many millers. In some instances, in fact most 
instances, this would be right, but here where the stock would probably 
be tolerably thin toward the last on the bottom reel, the product of the 
No. 16 cloth would be no finer than No. 14 cloth on the reel above, 
and it is desirable to get as much flour as we can from any set of rolls, 



422 


GRADUAL REDUCTION MlI.LING. 


though not always to get as much as we can from any one of them. 
For that reason we arrange on the bottom reel so that the flour may be 
taken a greater portion of its length, thus admitting of a judicious 
scalping upon the reels above. The tail and cut-off from the last reel 
is dust middlings. If the dust middlings product should be too soft, all 
that would remain to do would be to take a spout from the tail of the 
bottom reel of the third flour reel conveyor and run it into the elevator 
of the first dust middlings chop. This would take the flour out of the 
dust middlings and send it into the flour reels, that is, it would cut it 
round the rolls. If there should be any trouble in the feeding of the 
first dust middlings rolls, it would be on this account. Wherever there 
is such trouble, it indicates that there is too much flour stock running 
into the other material, and, as we know, if such flour stock be taken 
out and rebolted, in the reels of the rolls to which it was originally run, 
all of this trouble would be obviated. 

As the fifth break product is treated by itself, we will consider the 
reductions and separations given, and it would be well if the reels which 
handle the product of that reduction were to be arranged as here 
shown, that is, one above the other. It would be convenient to inspect 
all grades of stock in immediate proximity one to another. We show 
No. 6 rolls handling this grade of material. They are 9x18 inches in 
size, and have twenty corrugations to the inch. It is a usual thing to 
decrease the number of rolls and the proportion of grinding surface at 
this stage of the process, but it is a wrong thing to do. If any change 
is made, the proportion should be increased. It is difficult enough to 
get flour of the proper quality and middlings of a sufficiently high grade 
to work into patent flour from this reduction, and it is especially diffi¬ 
cult to do so when the proportion of grinding surface is reduced. The 
first scalping reel is clothed with No. 34 grits gauze, which is equivalent 
to No. o bolting cloth. The tail of this scalper goes to the sixth break 
in the usual manner, and the break goes into a scalping reel. The head 
of the scalping reel is clothed with No. 7 cloth, and the tail numbers, as 
shown, are 4 and 2. The tail of the No. 2 goes to the rough tailings, 
as does any proportion of the product of the No. 2, while the product 
of the No. 4 goes to the fine tailings purifier. This arrangement pre¬ 
vents the possibility of waste of good material. If the middlings are 
of proper grade to go into patent flour, they may be sent in that direc¬ 
tion, and if not, they may be sent around the purifiers into the rough 


GRADUAL REDUCTION MILLING. 423 

tailings. Kven if their character is questionable they should be sent to 
the purifiers and their grade elevated thereby. The product of the No. 
7 is sent into the hour reel immediately below this middlings scalper, 
which is clothed with No. 12 at the head. It is not necessary to take 
any more than a very small proportion of Hour from this reel. The 
scalping number is 6, which is one number coarser than the scalping 
number on the reel above. 1 he tail of the No. 6 may be sent to the 
first low grade, and the desirable portion of the product of this scalper 
may be sent to the third dust middlings. The cut-off from the No. 12, 
and the cut-off from the scalping product, is sent into the reel below, 
which is clothed with Nos. 14 and 16. The tail of the No. 16 is sent 
to the second dust middlings, and the cut-off from the Hour reel is sent 
to the third dust middlings Hour reel. This is for the purpose of pre- 
venting the third dust middlings from being too soft, and as this stock is 
very fine, it will find its proper place in this reel, and prevent liability of 
waste, in that it will go through the proper Hour numbers at the proper 
time. 

The sixth break has the same number of rolls and the same amount 
of grinding surface as does the fifth break. The corrugations are twenty- 
four to the inch. This number for this break seems to be a fixed fact. 
No one appears to question the desirability of using a coarser or finer 
cut roll. The product of the sixth break rolls is scalped on a centrif¬ 
ugal which is 8 feet long, and which is clothed with No. 36 wire. No. 
36 wire is equivalent to No. 1 cloth. The action of the centrifugal on 
bran stock is like that of a bran duster, and after the material has passed 
over the tail there is no need of sending it to the bran duster. All has 
been done for it that can be done by the action of the centrifugal. 
There are two conveyors under this centrifugal reel so arranged that the 
tail portion of that reel may be sent direct to rough tailings, and thus 
keep them out of the scalp reel below. The product of the upper con¬ 
veyor is sent into a Hour and tailings scalping reel below. This reel is 
16 feet long. The product of the No. 8 cloth is sent into the Hour reel, 
while any portion of the No. 4 cloth may be sent to rough tailings. 
The tail of that reel is also sent to the rough tailings rolls. Thus we 
will have coming to the rough tailings, material which will tail over a 
No. 8 and pass through a No. 1, but it is a low grade of material. Still 
there are nubs and other stock which lie between the corrugations of the 


424 


GRADUAL REDUCTION MILLING. 


rolls which contain a certain proportion of Hour, anti which will be 
reduced by the rough tailings rolls. After having passed through the 
No. 8 cloth, this stock is • sufficiently soft to bolt nicely on the reel be¬ 
low. In the case of its being very soft, if it should not bolt free enough, 
it is entirely possible to run in a little of the stock which passes through 
the No. 4, and thus liven it. The product of the Nos. 12, 14 and 16 
cloth of the Hour reel is first low' grade Hour. On winter wheat it would 
be of a grade equivalent to three-eighths St. Louis standard, that is, 
first-class lo\v grade Hour, a grade next to family. It is a mistake to 
send this Hour in with the other low grade, in that it is worth more 
money. The tail and cut-off from this Hour reel is sent to the first 
red-dog. 

None of the diagrams which have been presented have ever shown a 
seventh reduction of the wheat. The reason for this has not been that 
seven reductions were not better than six, but from the fact that six re¬ 
ductions are all that are usually considered, and that seven reductions 
or more are often considered unnecessary from a commercial stand¬ 
point, and might be considered as a finicky exhibition on the part of one 
who would seriously advocate their use. Now at the risk of being con¬ 
sidered too particular, the writer wall say that if six reductions are neces¬ 
sary on spring wheat—and we know that six reductions are used, and for 
that reason may be considered necessary—that seven reductions are 
equally necessary on winter wheat, for the purpose of getting all 
the Hour out of the wheat, which means getting all the money out of the 
wheat, that is possible. The writer has no hesitancy in saying that better 
results, better flour, more of it, and more money will be made by seven 
reductions than by six or any less number. However, seven reductions 
should not be attempted on a small mill, for the reason that the tempta¬ 
tion to run the stock in with other material for the purpose of making 
the separations would be too great to be overlooked, in most instances. 
In a mill of any size where there are seven reductions, the stock should 
be scalped and bolted on entirely separate reels, as much as if it were 
a mill by itself. It should have no connection with the other stock ex¬ 
cept through the means of the intermediate stocks. There would be 
first red-dog stock and second red-dog stock; otherwise, nothing which 
belonged in any other part of the mill. In the smaller mills there is a 
tendency to attempt to work this material in with other stock. The 


GRADUAL REDUCTION MI EUING. 


425 


product of the seventh reduction would probably be run in with the 
sixth, and the sixth is often mixed in with other higher grade products. 
Now while the seventh reduction is desirable, -we will repeat by way of 
emphasis that it ought to be handled entirely by itself—have no connec¬ 
tion with any other product, other than in the way mentioned. 




CHAPTER TXXXII. 


FIRST DUST MIDDLINGS—REDUCTION AND SEPARATION OF DUST MIDDLINGS 
—SECOND DUST MIDDLINGS—ROUGH TAILINGS-—PURIFICATION, REDUC¬ 
TION AND SEPARATION OF ROUGH TAILINGS-RED-DOG-ORIGIN OF 

RED DOG STOCK—GRADING OF RED-DOG STOCK—SECOND RED DOG 

REDUCTION OF RED DOG BY MILLSTONES—FLOUR FROM RED DOG 
REDUCTIONS. 

The first dust middlings, which is composed of the tail and cut off 
from the last second middlings reels, the tail and cut-off from the last 
break flour reels, and the cut-off from the purified tailings flour reels, is 
all stock which will pass through a-No. 9 cloth, and considering the 
material from which it was produced, it will be a stock of most excellent 
character, the flour from which will be of a character next to patent in 
quality. The only reason that the dust middlings are not purified by 
the ordinary means is that the middlings are too fine, and the only puri¬ 
fication there is for them is through the means of their gradual reduc¬ 
tion by rolls, and of the scalping of the material, which may be done 
from the reduced stock. The product of the reduced middlings, which 
is by means of smooth rolls, is sent on a reel clothed with Nos. 12 and 
14 cloth, and a tail of No. 8. Now while the middlings have all passed 
through a No. 9, and at the same time that the No. 8 tail scalper is 
coarser than the original number through which they passed,'it will be 
found that a certain proportion of material will pass over the tail of this 
No. 8, for the reason of its flattening by the roller reductions, and this 
will occur, however careful that reduction may be. There will be a little 
material which it would be well not to send over the tail of this reel, 
however. That little will be unavoidable. At the same time that there 
will be some good stock pass this way, there will be much that would 
properly belong with the rough tailings, in which direction it is sent. 
The stock which passes through the tail of this reel will probably be of 
a character to justify its passage in the same direction. Often all can 
be sent into the lower reel, in which event it will either be flour or sec¬ 
ond dust middlings. In previous chapters a great deal has been said 


GRADUAL REDUCTION MILLING. 


427 


about dust middlings, and much that should be known and understood 
by those who mill. But it is hardly in place to repeat it here. For that 
leason we will drop their consideration and take up the second dust 
middlings. 

1 he second dust middlings is reduced upon two pairs of 9x18 rolls, 
and is of a material next in quality to the first dust middlings, and we 
will say here what might have been said in regard to first dust middlings, 
that the reduction should be considered as a sizing operation. More 
Hour will be made in this way than by a close reduction, for, if we con¬ 
sider, we will remember that all of the stock which goes on to these 
rolls is fine—most of it next to Hour in size, most of it that which will 
pass through a No. 9 cloth, some of it that which will pass through a 
No. 10 or 11, For that reason very little reduction is required; it 
should be merely a sizing operation, and not a squeezing or mashing. 
The arrangement of the reels for the reduction of this second dust mid¬ 
dlings is like that shown for the first dust middlings, excepting that there 
is no No. 14 cloth on the first reel. 

The third dust middlings rolls are 9x14 inches in size, and handle a 
grade of stock less uniform in size than that of the first and second dust 
middlings. It contains a small proportion of material which, in 
some instances, is a little coarser. It is next to the first red-dog 
stock in quality, though the Hour produced is relatively a good deal 
higher in quality. The size of the rolls admits of a very careful and 
very good reduction. The clothing of the reels is exactly the same as 
that for the second dust middlings, with the same general purpose in 
view; therefore, we need not repeat what has been said with reference 
to that purpose. A switch path is shown from the flour break of the 
third dust middlings, which indicates that the flour may be sent either to 
the first low grade or to the clear Hour. 

In considering the rough tailings product, we will have in mind that 
what has been said in regard to the production of this stock has been 
carefully read and considered, and for that reason we will not recapitu¬ 
late or consider anything that has gone before, only remembering that 
it is a rough, branny grade of stock, which contains a good deal of bran 
and quite a proportion of fine soft material which would be sent to feed 
excepting that there is mixed with it other better material, and it is 
altogether a stock of very low character. We send this material into a 
reel to be graded, for the reason that it is hardly possible to grade it as 


428 


GRADUAL REDUCTION MILLING. 


it is produced. This reel is clothed with No. 2 cloth at the head, and 
No. 1 at the tail. Whatever passes through the No. 2 cloth is sent to 
one pair of 9x14 rolls, and whatever passes through the No. 1 cloth is 
sent to an aspirator, and the stock which passes over a No. 1 cloth, to 
another aspirator. From this material will be drawn out quite a propor¬ 
tion of fine bran. We will say here that it would be well to attach a 
slight suction to the grading reel as well, which would also take out 
some of this material. The bran which would be taken out from these 
aspirators will be so thin and light that it will be sent to the feed. This 
whole apparatus is simply for purifying purposes, a means of the purify¬ 
ing of the rough tailings in so far as that operation is possible, excepting 
as it is continued by the use of the smooth rolls. 1 hese rolls crush this 
material, which has been freed from all the light, fine, branny matter 
which would otherwise be pulverized and run into the Hour, and it passes 
into the first reel, which is clothed with Nos. 6 and 2 cloth. The tail of 
the No. 2 goes to the bran duster, as does any desirable portion of the 
product of that cloth. The product of the No. 6 goes into a reel 
clothed with Nos. 12 and 14, which produces first low grade tlour, or in 
some instances this might be run in with the clear Hour. The cut-off 
from that reel may be sent directly to the second low grade or into the 
first low grade reels, or to the first red-dog rolls, as shown; though it 
must be borne in mind that whenever this stock is soft enough to make 
the first red dog roll feed badly, then it is soft enough to be run in with 
the flour, or, if not that, it should be sent around the rolls and into the 
reels. 

The origin of first red-dog stock has been duly considered in the past, 
and is a stock intermediate between third dust middlings and the finer 
red-dog stock. It is a grade of material which will produce XX or 
XXX flour, and which should pass to the same grade as that produced 
by the sixth'reduction rolls. 'There is a short piece of No. 14 cloth at 
the head of the first reel, which separates the first reduced red-dog 
stock, and then there is a piece of Nos. 7 and 2 at the tail. The tail of 
the No. 2 may be sent to the feed, the product of the No. 2, the second 
red-dog and the product of the No. 7, and the cut-off of the No. 14 to 
the second reel. The flour product of course goes to the first low 
grade, and the cut-off and the tail from the second grade goes to the 
second red-dog buhrs. There is nothing better for the second red-dog 
reduction than the millstones. They should have about 4 inches draft 


FREE HUNDRED BARREL MILL, 








































































































































































































































































































































































































































































































































































GRADUAL REDUCTION MILLING. 


429 


and run about 130 or 140 revolutions a minute; should be dressed 
so as to reduce the stock, and should be run strictly for that purpose. 
This reduction should be regarded as the last chance, and the most 
should be made of it. The Hour will be low in grade under any circum¬ 
stances. The rolls could not reduce this material. They would make 
very little Hour. The stock would be too Hat. It would be much like 
grinding feathers. Nothing but a millstone will have much effect upon 
it. The course of the stock is clearly shown in the diagram. One mill¬ 
stone would do most of the work. Two are necessary, in order that 
one may be taken up from time to time for the purpose of cracking, 
with good, heavy, well-defined crackers. The bran duster takes all of 
the feed stock excepting the tail of the sixth reduction scalper; that is, 
it takes everything except the bran. It is really a fine feed duster 
rather than a bran duster. It should be clothed with about No. 110 
,vire, which is equal to about No. 10 cloth. The product should be sent 
to a centrifugal reel, for the purpose of rebolting the stock. The flour 
will be sent to the low grade, and the cut-off back to the red-dog. This 
is the only return we have in the mill. 





















































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